Six commercial flights between Paris and Los Angeles have been canceled due to security concerns, the French government and Air France said Wednesday.

The U.S. Embassy in Paris asked the government to cancel the Air France flights scheduled to depart Wednesday and Thursday "for security reasons," a ministry spokesman said. The U.S. Department of Homeland Security had been meeting with French officials in recent days over concerns about a possible terrorist attack.

The French prime minister's office said in a statement that the cancellations had been prompted by information obtained "in the framework of the French-American fight against terrorism."

Three of the flights were scheduled to depart Wednesday  two from Paris and one from Los Angeles. Air France gave the flight numbers as 68, 69 and 70.

The three other flights were scheduled to leave on Christmas Day  two from Los Angeles and one from Paris. Air France listed those flight numbers as 68, 69 and 71.

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

"These flights have been canceled for security reasons. It comes out of a disposition given by American authorities in France," said Anna Laban, deputy press attache at the French consulate in Los Angeles.

The cancellations came almost exactly two years after the arrest of so-called "shoe bomber" Richard Reid.

Reid, a British convert to Islam, was arrested on Dec. 22, 2001, when he tried but failed to detonate explosives in his shoes on American Airlines flight No. 63 from Paris to Miami. He was sentenced to life in prison.

Representatives of the Federal Aviation Administration (news - web sites) and Los Angeles International Airport said they had no information about the cancellations.

The U.S. Department of Homeland Security had been meeting with officials from the French government in recent days over concerns about a possible terrorist attack, a spokesman for the Transportation Security Administration said Wednesday.

Homeland Security Secretary Tom Ridge has personally been involved in the briefings with the French officials, as well as officials from other nations, TSA spokesman Brian Doyle said.

Doyle refused to name other countries that had been contacted.

"We're talking to our counterparts in other countries about security concerns," Doyle said.

Security at Los Angeles International Airport had already been tightened to its highest level in two years.

With 2.6 million travelers expected to use the airport between Dec. 19 and Jan. 4, airport officials on Wednesday searched cars bound for terminals and prohibited curbside dropoffs and pickups.

Los Angeles Mayor James Hahn announced the new restrictions late Tuesday, calling them "a precautionary measure during a period of heightened readiness."

Los Angeles operates one of the busiest airports in the world. It has twice been targeted for attacks in recent years  a foiled bomb plot planned for around New Year's Day 2000, and a shooting at a check-in counter that left three dead on July 4 last year.

The airport was shut down for two days after the Sept. 11, 2001, terrorist attacks, and private vehicles were kept out of the central road area for two months.