Kia Ora Gaza's Lyn Doherty was selling T-shirts to raise awareness and funds. She said Gaza residents were enduring a severe humanitarian crisis.
"What they need is the bombing to stop," Doherty told the Herald on Sunday.
"They need a ten year ceasefire with the siege broken."
Green MP Catherine Delahunty addressed the crowd and said her party supported the imposition of economic sanctions on Israel.
"Let's get real about this issue," she said.
Mana Movement supporter and adventurer Busby Noble was also present.
"It's all about everybody having a [fair go] really," Noble said when asked why he was attending. "We should be making a noise for those less fortunate than ourselves."
Some protesters held banners calling for the Israeli ambassador's expulsion from New Zealand.
Large crowds gathered in the same location last weekend. Today, a speaker at Aotea Square said people should keep protesting in central Auckland every Saturday, until Gaza's residents achieved "freedom and justice."
Unite union's Mike Treen said today's turnout was heartening.
Protesters decided again to march to the United States Consulate on Customs St. Treen said this was because US military aid enabled Israel to launch acts of aggression against Palestinians.
Between speeches, a lone protester yelled "shame on you John Key, bring back David Lange."
The march itself started at about 2:55pm and protestors moved down Queen Street.
Among various chants and songs, protesters held up their hands, yelling "blood on your hands" and "Israel, USA, how many people did you kill today?"
Protest organisers told the crowd they planned to stage a "die-in" outside the Civic Theatre. But they decided instead to have the die-in near the intersection of Queen and Victoria streets, near the Whitcoulls building.
Individuals played dead to symbolize lives lost in the conflict. Then a mass "die-in" occurred with all marchers told to lie down on the ground. Some instead had to sit as the street was not wide enough to allow everyone to lie down.
There was a small police presence, accompanying the crowd and directing traffic. Police were earlier keeping an eye on a small group of youths on the fringe of the protest but there were no major problems with the group.
The demonstration reached the US consulate at about 4pm. Many of those in attendance sat in Customs St outside the consulate. "Let's go inside," one man yelled. He was ignored.
"From the river to the sea, Palestine will be free," marchers chanted, referring to the land between the Mediterranean Sea and the River Jordan, most of which is in Israel.
A brief squabble broke out about 20m in front of the consulate when five youths who were earlier standing on an Israeli flag started ripping it.
A man calling himself a protest organiser later approached a photographer, asking if he had taken photos of the flag-ripping incident. "They're a small minority and they're ruining it for everyone," he told the photographer.
Placards showing messages of support for the people of Gaza and condemnation of the ground offensive were placed in front of the consulate.
More people made speeches and read poems before the demonstration ended as it did last weekend - with a performance of Roger Fowler's "We are all Palestinians".
Fowler was in Gaza when Israel bombed the area in late 2012. He said the current situation was far worse.
Fowler's friend, Julie Webb-Pullman, spoke to the Herald on Sunday from al-Shifa hospital in Gaza last night, where she was volunteering as a human shield.
"There've been sirens, ambulances all night. When I came in, past the morgue, there was the queue of people waiting to collect the bodies."
She said there had been frequent drone attacks and Israeli Air Force F-16s flying over neighbourhoods.
"Last night a missile struck 100m from a children's hospital," she added. "It's a fairly constant stream of dead and wounded coming in."
Webb-Pullman said Gaza's health services were under appalling strain. She said doctors did not have enough equipment or medical supplies and were having to make heart-breaking decisions on which patients they could save.
She said Israeli government claims Hamas was preventing civilians from leaving were incorrect.
"We stayed because there is nowhere to go. There are tanks shelling us. You tell somebody to leave their house and walk out in front of a tank."
"There was a massive big explosion near my house that rattled the whole house...I don't know what the target was yet, but it was obviously a pretty big missile that hit," she said.
Webb-Pullman said she was determined to stay, as were most people in Gaza. She wondered if "too much blood had been spilled" for the conflict to ever be resolved.
When called again, just half an hour into the ceasefire, Webb-Pullman said Gaza's residents were trying to conduct routine daily affairs before the conflict resumed.
"People are out stocking up...there's lots of traffic," she said at 5:45pm New Zealand Time. "Israel has virtually never honoured a ceasefire, they always break it...but 12 hours is something."
Yet she said the situation for Gaza's medical services was still bad.
"Yesterday I think two ambulance drivers were killed," she said. "One of the human shields got hit in the head and was bleeding."
Plans for a seven-day truce between Israel and Hamas have been unsuccessful. US Secretary of State John Kerry has arrived in Paris for talks on the conflict.
Israel says the offensive is designed to cripple Hamas' network of tunnels and rocket-launchers. Opponents of the action say Israel's offensive is causing a humanitarian disaster in Gaza, which already faces crippling poverty.
A leaked document, purportedly outlining Kerry's plans for a truce, was discussed on Al-Jazeera as the ceasefire came into effect this evening.
Kerry reportedly wanted to discuss fishing rights, the payment of Gaza's civil servants, and opening Gaza's border crossings as part of talks to resolve the conflict. It is also believed Kerry planned to advise Israel to pull its military forces completely from Gaza. Qatar and Turkey were also involved in attempts to broker the deal.
At least 857 Palestinians and 39 Israelis have died in the offensive, with an estimated 5700 Palestinians injured.
The Ministry of Foreign Affairs and Trade said today there were 90 New Zealanders in Israel and 2 in the West Bank registered on SafeTravel. It did not provide figures for Gaza. At least 26 New Zealanders have left the region in the last seven days.
