U.S. officials were tight-lipped about what else they know about Kouachi and his brother Chérif, 32, including whether they fought in the Middle East with extremist groups.
Witnesses said the attackers claimed allegiance to al-Qaida in Yemen.
It would not be unusual for known extremists to be placed on the no-fly list, particularly since Chérif Kouachi had served 18 months in prison for recruiting militants to fight the U.S. in Iraq.
Manhunt continues north of Paris
Elite French security forces deployed helicopters in a night-time manhunt for the two brothers accused of slaughtering 12 people in an Islamist attack on a satirical magazine in Paris.
"The search will continue tonight with the help of five helicopters," a police source told AFP in the tiny village of Villers-Cotterets, northeast of the capital, where the suspects, believed to be brothers Cherif and Said Kouachi, earlier robbed a petrol station and abandoned their getaway car.
French gendarme guard a gas station where the suspects of a shooting at a Paris newspaper office were reportedly spotted in Villers Cotterets, 80 kilometers northeast of Paris. Photo / AP
The fugitives were thought to be behind yesterday's bloodbath at Charlie Hebdo magazine, the worst terrorist attack in France for half a century, which the gunmen said they carried out as revenge for the weekly's repeated publication of cartoons mocking the Prophet Mohammed.
Read more: Who are Cherif and Said Kouachi?
About 24 hours into the manhunt, they were identified after robbing the village petrol station, 80 kilometres from Paris, before fleeing again, possibly on foot and still armed with at least a Kalashnikov, police said.
Special police units rushed to the scene, backed by helicopters.
Moving methodically, officers in heavy black bulletproof vests went house to house, rifles at the ready, under the nervous eyes of local residents. An AFP reporter saw them storm one house.
The fact that they didn't find the suspects only added to the mounting tension.
"I live near the woods," said village resident Roseline, a grandmother. "I'm afraid. Night is falling and they could be hiding nearby."
A map showing the location of Villers-Cotterets, where the suspected gunmen were said to have robbed a petrol station before evading police again.
A maximum security alert declared in the capital Wednesday was expanded to the region where the manhunt took place.
Islamic State, the militant group sowing terror across swathes of Iraq and Syria and calling for global jihad, hailed the brothers as "heroes" on its Al-Bayan radio station.
In a further sign of the attackers' motives, a source close to the case said that Molotov cocktails and jihadist-style flags had been discovered in another getaway vehicle used by the attackers and abandoned in Paris.
French Interior Minister Bernard Cazeneuve announced that an international meeting on terrorism would take place in Paris on Sunday, including US and European officials.
French armed police officers patrol near a farm as they search for suspects in the attack on Paris offices of the newspaper Charlie Hebdo, in Longpont, northeast of Paris. Photo / AP
Highest security level extended
France has extended the highest security alert level already in place in greater Paris to the northern Picardy region where police have zoned in on two suspects in the magazine massacre.
"The prime minister has decided to extend the attack alert level to Picardy," Prime Minister Manuel Valls' office said this morning NZ time.
Britain, meanwhile, has stepped up security at ports serving France following the attack in Paris, as the MI5 intelligence agency offered French counterparts its "full support".
The terror threat level in Britain remains at "severe" and officials said the measures were a precautionary measure following the slaying of 12 people at Charlie Hebdo.
In rare public comments, MI5 Director General Andrew Parker said the attack was a "terrible reminder" of the threat facing Western nations.
Eiffel Tower dims lights
The lights have gone out on France's iconic Eiffel Tower in a sombre tribute to the 12 people killed in the attack on the Paris satirical magazine Charlie Hebdo.
The lights normally illuminating the 324-metre-tall monument at night went out at 8pm local time (8am NZ time).
It happened as a demonstration of thousands was in full swing on the other side of the city, in Republique square, for the second night running.
Other events will be held in the French capital over coming days to mark the outrage over Wednesday's attack on Charlie Hebdo, and to assert the right to freedom of expression - a value France has long cherished and sought to protect.
Tensions high in France after deadly attack on newspaper
On Wednesday heavily armed men with possible links to al-Qaeda methodically murdered 12 people during an on the French satirical magazine Charlie Hebdo, famous for its caricatures of the Prophet Muhammad.
As tensions mounted in Paris, police last night said two police officers -- one a woman -- and a street sweeper had been shot in Montrouge on the city's southern edge. The policewoman died. It was not known whether the shootings were connected. The gunman in the latest incident, believed to be wearing a bullet-proof vest, was still on the run last night, according to Interior Minister Bernard Cazeneuve.
The attacks proved fatal for eight journalists, two police officers, a maintenance worker and a visitor. Photo / Getty Images
French soldiers disembark at Le Bourget airport, north of Paris, as part of deployment of soldiers to enhance security in Paris. Photo / AP
In a separate incident an explosion at a kebab shop close to a mosque was reported in a town in the east of France, near Lyon. There were no reports of casualties.
In Wednesday's Charlie Hebdo attack, eight journalists, two police officers, a maintenance worker and a visitor were killed. Eleven people were wounded -- four seriously.
France raised its terror alert system to the maximum -- Attack Alert -- and bolstered security with more than 800 extra soldiers to guard media offices, places of worship, transport and other sensitive areas.
It was reported last night that seven friends and associates of the three suspects had been arrested.
Paris Mayor Anne Hidalgo said she felt an "absolute horror at the attack" and thanked other leaders for their support. Support also mounted across the world, including from US President Barack Obama, who condemned the violence.
Mobile users tap here to watch Obama: Paris shootings a 'cowardly evil attack'
"A universal belief in the freedom of expression is something that can't be silenced because of the senseless violence of the few," he said.
More details of the attack emerge
Details of the slaughter emerged throughout the day, with shaken witnesses giving chilling accounts.
It began at 11.20am when two heavily armed gunmen climbed out of a small black Citroen. One was reported to be carrying a rocket-propelled grenade launcher and both were armed with Kalashnikovs.
Leaving a third man in the car, the pair walked up the tree-lined Rue Nicolas-Appert to No6.
"Is this Charlie Hebdo?" they screamed at two maintenance workers. The workers told them the magazine was two doors down.
The men shot one of the workers and moved on to No 10.
At 11.25am cartoonist Corinne Rey arrived at work with her young daughter to find the gunmen waiting. They forced her to punch in the four-digit security code and frogmarched the mother and daughter upstairs.
Inside the Charlie Hebdo office, reporters and editors were holding their morning news conference. The first sign of trouble came when a worker in an office across the corridor heard "a huge boom".
"Then someone opened the door to our office and asked where Charlie Hebdo was. He had a rifle. We backed away," she said.
Seconds later the gunmen stormed into the newsroom, calling out the names of each of their targets before shooting them dead.
Police officers stand guard in front of a building where forensic police officers look for evidence relating to the suspects of the shooting attack. Photo / AP
The victims included editor Stephane Charbonnier, 47, his police bodyguard Franck Brinsolaro, 49; renowned cartoonists Georges Wolinski, 80, Bernard Verlhac, 57, and Jean Cabut, along with 68-year-old writer Bernard Maris.
Writer Laurent Leger managed to call a friend and sound the alarm.
"Call the police. It's carnage, a bloodbath. Everyone is dead," he said, and then the line went dead.
Another journalist in the office sent a text message to a friend saying: "I'm alive. There is death all around me. The jihadists spared me."
Police would later reveal that two "calm and determined gunmen" were hunting Charbonnier.
"It was Charb they were targeting. The two attackers looked for him in the room, shouting, 'Where is Charb? Where is Charb'?" they said. "They killed him then sprayed everyone else."
Other workers took refuge on the roof as the terror unfolded.
Journalist Benoit Bringer said: "There were very many people in the building. We evacuated via the roof just next to the office."
According to witnesses the gunmen screamed out as they left that they had "avenged the prophet" and "Allahu akbar" (God is greatest).
Soon after, another witness said the Charlie Hebdo office was "like a butcher's ... here are so many dead."
At 11.50am the gunmen returned to the street and headed towards the Citroen. The killers began to drive away, but encountered a police patrol car further down the street. They sprayed the police car with bullets. A short time later they came upon a wounded officer.
The gunmen descended on the officer, shooting him at close range as he begged for mercy.
Walking back to the getaway car, a gunman shouted: "We have avenged the Prophet Muhammad, we have killed Charlie Hebdo."
The police officer has been identified as Ahmed Merabet, a 42-year-old married Muslim man. Meanwhile, back at the magazine office, a man stumbled into the street crying "they are all dead".
Doctor Gerald Kierzec was among the first on the scene.
"There was a first body lying in the lobby. Then I took the stairs which were covered in blood. When I got to the second floor, there were bodies lying one on top of another. It was carnage ... "
- Staff reporter, Daily Mail, AP, and Independent
Eyes on 40 NZ names
The Government will not beef up security further for the Cricket World Cup in response to the terror attacks in Paris but says it's keeping a close eye on international events in case upgrades are needed.
And it has been revealed 40 people are being monitored in New Zealand for their involvement in terrorism-associated activity. The security services are monitoring about 80 people - with 40 of those on a current security watch list.
A New Zealand Intelligence Community spokesman said yesterday the main focus of security services was on people "travelling to Syria to engage in fighting" and those who had tried but had their passports cancelled.
"The remaining people on the watch list are involved in funding terrorism, radicalising others or are becoming radicalised themselves."
Prime Minister John Key has previously warned of the heightened risk of a terror attack at the Cricket World Cup, hosted by New Zealand and Australia, and cited this as a reason for urgently passing anti-terror laws last month.
Duty minister Chris Finlayson said yesterday security was being taken very seriously and had been built into the Cricket World Cup planning from an early stage.
"Any armed incident, including the tragic events in Paris, is an opportunity for us to learn and identify lessons that could help us in future events."
The World Cup next month and in March includes nations which have a military presence in the Middle East or have been targets of domestic terror attacks, such as Australia, Canada and England.
Cricket World Cup officials said they took their lead from the Government, and confirmed security was not being reviewed in light of the Paris attacks.
A spokesman reaffirmed that security measures had been planned for two years.
- Isaac Davison
-Staff reporter, Daily Mail, AP, and Independent
