Three Paris-Los Angeles commercial flights were canceled due to security concerns, the Interior Ministry said Wednesday.

An Air France spokeswoman confirmed that a flight due to leave Paris at 1235 GMT for Los Angeles had been grounded "for security reasons."

According to officials from the office of French Prime Minister Jean-Pierre Raffarin, the move was based information "gathered in the framework of Franco-American cooperation in the fight against terrorism."

Air France said it was working to arrange accommodations for stranded passengers.

Meanwhile, US authorities are investigating a threat to Air France planes to Los Angeles that prompted the cancellation of the three flights from Paris on Wednesday, law enforcement officials said.

France says no other flights to be canceled except 6 Paris-LA flights

The French government said Wednesday no other flights will be canceled after deciding to cancel Air France's six Paris-Los Angeles commercial flights due to security concerns.

The cancellation was due to the principle of precaution though there is no certainty that the security has been threatened, said the government following a meeting gathering officials from the ministries of foreign affairs, interior affairs and transportation.

Prime Minister Jean-Pierre Raffarin made the final decision on the basis of information gathered in the framework of French-American cooperation in the fight against terrorism, said the government in a statement.

Air France said it was working to arrange accommodations for stranded passengers.

Meanwhile, US authorities said they are investigating a threat to Air France planes to Los Angeles that prompted the cancellation of the three flights from Paris on Wednesday.

In Paris, the canceled flights are AF068, scheduled to take off at 1335 (1235 GMT), AF070 at 19H00 (1800 GMT) on Wednesday and AF068 at 13H35 (1235 GMT) on Thursday.

In Los Angeles, the canceled flights are AF069 on Wednesday andAF071 and AF069 on Thursday.

In Paris, each of the passengers on Wednesday's AF068 has been thoroughly checked but no element of threat was found, said the French Interior Ministry.

Reports said the flights were canceled after the US embassy in Paris warned it feared they might be used for terrorist attacks.

Officials in Los Angeles said the US Federal Bureau of Investigation and the Department of Homeland Security were probing an unspecified threat, but refused to divulge details.

The alert came as US authorities stepped up surveillance on all flights arriving in the United States. The government on Sunday raised the nation's terrorist threat level from "elevated," or yellow, to "high," or orange.

US officials ask Air France to cancel flights due to "credible" threats

US officials had given Air France information on "credible" threats before the airline canceled several flights between Paris and Los Angeles on Wednesday, officials from US Homeland Security Department said.

The French government said Wednesday it had canceled six Air France flights between Paris and Los Angeles Wednesday because of fears of a possible terrorist attack. The three canceled flights from Paris were AF068 and AF070, both scheduled on Wednesday, and AF068 on Thursday. The three return flights from Los Angeles were also canceled.

US authorities said they are investigating an unspecified threat to Air France planes that prompted the flight cancellations. The French government said the United States handed it the names of suspicious people who may have intended to board those flights but no element of threat was found.

Reports said the flights were canceled after the US embassy in Paris warned it feared they might be used for terrorist attacks.

The news of cancellations came as US officials said a high volume of good-quality intelligence indicated that the al-Qaida terrorist network attempted to attack the United States during the Christmas holiday.

US Homeland Security Secretary Tom Ridge on Sunday raised the nation's terrorist threat level to orange, the second-highest level of a five-color warning system put in place in March 2002, from the middle level of yellow.

Ridge said intelligence reports indicated that "al-Qaida continues to consider using aircraft as a weapon," adding: "They are evaluating procedures both here and abroad to find gaps in our security posture that can be exploited."

Security has been beefed up around major US cities such as New York and Washington and critical infrastructures such as airports, nuclear facilities, power plants and oil refineries. The Pentagon announced Tuesday it would increase the number of warplane patrols over major cities around the country and boost air defense around Washington.

A Pentagon official told the Cable News Network on Wednesday that the possibility of an attack using an airliner -- either one coming to the United States from Mexico or an Air France plane -- remains a major concern.

Earlier Wednesday, The Washington Post reported that new US intelligence is prompting stepped-up scrutiny into whether foreign airports and airlines have been penetrated by individuals sympathetic to terrorist groups.

US officials have questioned a small number of crew members in recent weeks after their names appeared to be similar to those on the FBI's "watch lists" of suspected terrorists, the report said.

Passengers coming into at least one major US international airport on Air France and flights from Mexico will be subject to more security procedures beginning Wednesday, the newspaper quoted aviation industry officials as saying.

French officials said there have been "some very intense exchange" between US and French officials on efforts to "share intelligence and to reflect on how we could prevent any possible terrorist attacks," the Post said.

Los Angeles int'l airport on highest alert

The toughest security measures were imposed Wednesday at Los Angeles International Airport (LAX) on the eve of Christmas.

No curbside drop-off or pickup by private vehicles is allowed as of Wednesday morning, a measure that will remain in force through Jan. 4. With curbside access limited to taxis, limousines and shuttle buses, private vehicles arriving at LAX are being directed to parking structures.

"I want to assure you that this is just a precautionary measure," Los Angeles Mayor Jim Hahn said late Tuesday night. He said the measure was taken in consultation with local, state and federal law enforcement agencies.

Due to extra security measures enforced at the LAX, passengers are asked to arrive about three hours before the flight and not to wrap Christmas gifts for security checks.

The measure was imposed as the latest of a series of security measures taken by the second largest US city as the whole nations braces for possible attacks against US targets by terrorists using hijacked airliners like the Sept. 11, 2001 attacks.

The US Homeland Security Department on Sunday raised the nation' s terror-alert level from yellow to orange, citing reliable intelligence that terrorists will launch a major attack on US targets.

Amid concerns that terrorists were trying to infiltrate foreign flight crews, LAX spokesman Paul Haney said that some members of foreign flight crews arriving at LAX were being checked closely by the Bureau of Customs and other federal inspectors.

"Certain crew members are getting extra scrutiny as they come into the country," Haney said.

On Wednesday, the French government canceled three LAX-bound Air France flights at the request of the US government for security concerns.

(Xinhua News Agency December 25, 2003)