Searchers turned up no evidence of explosives on a Paris-bound Air France plane that was grounded after French intelligence authorities warned that terrorists might be planning to blow it up, Venezuela's government said Sunday.

More than 60 technicians, bomb experts and a canine team made two exhaustive searches of the aircraft and passenger luggage Saturday night and a third one Sunday with representatives of the airline, Interior Minister Miguel Rodriguez Torres said.

He said that although no signs of any explosives were found, authorities would closely monitor all Air France flights entering and leaving the country.

The precise nature of the bomb threat was not known, but Rodriguez Torres said French authorities passed along information from a credible source that a terrorist group was seeking to put a bomb aboard an unspecified flight from Caracas to Paris, or vice versa.

"We don't want to speculate on the motives because the information comes directly from French intelligence services," Rodriguez Torres told state TV on Saturday.

In Paris, the French Interior Ministry said Sunday that France immediately alerted Venezuelan authorities upon learning of a potential threat to the route, which is served only by Air France.

"It is obviously the principle of precaution," Interior Ministry spokesman Pierre-Henry Brandet said. "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 just before its scheduled 7:25 p.m. departure that it was being delayed so the Airbus A340-300 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.

"They never told us anything," said Marbella Covino, a 22-year-old student.

The passengers were put on the Air France plane Sunday and it left Caracas just before 4 p.m. local time, airport officials said.

Venezuela's intelligence agency declined to comment on the threat, saying it wasn'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 an Air France flight to Paris.

Brandet, of the French Interior Ministry, said the drug bust was among several leads being investigated.

France is involved in two 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 U.S. 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 U.S. 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 there are no known operational cells in the region. Instead, the activity of groups including Hezbollah and Al Qaeda appears to be limited to fundraising and money-laundering, the report said.