In Paris, the French Interior Ministry said Sunday that France immediately alerted authorities upon learning of a potential threat to the route, which is served only by Air France.
"It is obviously the principle of precaution," said Interior Ministry spokesman Pierre-Henry Brandet. "We cannot allow the least risk, run the least risk for passengers." He provided no details on the measures taken and refused to comment on the nature of the threat or its origin.
An Air France press officer who spoke on condition of anonymity because of company policy said the carrier was working "in close collaboration" with airport and government authorities.
Stranded passengers said they had cleared immigration Saturday evening and were preparing to board Air France flight 385 when they were told at the last minute that it was being delayed so that the Airbus A340-300 aircraft could be checked. No reason was given.
"We only learned reading Twitter that it could've been a bomb," said Jesus Arandia, a 52-year-old university professor.
About 100 angry passengers surrounded the Air France check-in counter to protest the airline's failure to keep them informed or immediately provide alternative travel arrangements. Around midnight, the airport announced the flight was rescheduled for Sunday afternoon.
"They never told us anything," said Marbella Covino, a 22-year-old student.
The Air France office in Paris said Sunday that passengers from the postponed flight were being put on a flight that will leave Caracas at 8 p.m. local time.
Venezuela's intelligence agency declined to comment on the threat, saying it isn't authorized to discuss the case.
Security breaches have been detected before at Venezuela's main international airport.
In September, several Venezuelan soldiers stationed at the airport were arrested after French authorities made their biggest cocaine bust ever, seizing 1.4 tons of narcotics that were smuggled in 31 suitcases aboard another Air France flight to Paris.
Brandet, of the French Interior Ministry, said the drug bust was among several leads being investigated.
France is involved with two ongoing military interventions in former African colonies, in Mali where it routed Islamic extremists from the north and in Central African Republic where French troops moved in earlier this month to help stabilize the country, disarming militia to stop sectarian violence.
The US has warned that Middle Eastern terror groups have tried to make inroads in Venezuela, taking advantage of political cover provided by the late President Hugo Chavez's outreach to Iran and Syria, whose governments the US considers state sponsors of terrorism.
Still, even while criticizing the lack of anti-terror cooperation from Venezuela, the State Department in its most-recent assessment of terrorist threats in the Western Hemisphere said that there are no known operational cells currently in the region. Instead, the activity of groups including Hezbollah and al-Qaida appears to be limited to fundraising and money-laundering, the report said.
-AP