The French retaliated within minutes by shooting down the jets, Russian-made Su-25 fighter-bombers, apparently under direct order from French President Jacques Chirac.

Loud explosions were heard early today in Abidjan, the Ivory Coast's main city, and heavy gunfire could be heard as thousands of anti-French demonstrators marched toward a French military base, Reuters reported. A witness said a French military helicopter fired warning shots into a lagoon crossed by two bridges that lead from the city center toward the French base and the airport.

Col. Henri Aussavy, the spokesman for the 4,500-member French peacekeeping mission in Ivory Coast, said in a telephone interview that 23 French soldiers had also been wounded in the airstrikes. He said it was unclear whether his forces had been intentionally hit. ''We don't know if it is a deliberate attack or an error,'' Aussavy said.

On state-run television Saturday evening, Desire Tagro, a spokesman for the Ivory Coast president, said the raid was targeted instead at a rebel base near Bouake. Tagro said the attacks on Bouake had been designed to ''reunify the country.''

The Associated Press quoted an Ivory Coast government minister as saying it was ''a mistake'' but then questioning whether its warplanes were responsible. ''It was a mistake. We didn't aim to hit them,'' said Sebastien Dano Djeje, a Cabinet member.

In any event, the latest development plunges Ivory Coast, the world's largest producer of cocoa, into fresh chaos. Since civil war erupted in 2002, the French, who exercise significant economic influence in their former colony, have been accused of aiding rebels and have repeatedly come under attack by supporters of President Laurent Gbagbo.

At an emergency session convened Saturday afternoon, the U.N. Security Council condemned Saturday's airstrike, backed the French response and signaled that it would consider ''individual measures'' in the near future - in other words, possible penalties for individuals who violate international agreements.

France also sent three Mirage fighter jets to Gabon, in Central Africa, and deployed additional troops to protect its citizens in Ivory Coast.

Late Saturday, Reuters said the French Defense Ministry and a U.N. spokesman in Ivory Coast had confirmed that French troops had destroyed three Ivory Coast attack helicopters in Yamoussoukro, the capital.

In Abidjan, French and Ivory Coast soldiers traded gunfire at the airport, and government loyalists took to the streets, wielding machetes and axes, according to wire service reports. A French school was set on fire. Gunfire could be heard in the capital on Saturday night.

The spokeswoman for the U.S. Embassy in Abidjan, Ergibe Boyd, said it had received a report from the French that an unidentified U.S. citizen was also killed in the airstrike by the military.

The war has partitioned Ivory Coast between the rebel-held north and the government-held south, despite a tenuous cease-fire signed in May 2003 and monitored by the French forces and 5,240 U.N. peacekeeping troops.

The bombings on Saturday followed two days of air attacks by the government on rebel-held positions in the north of the country. On Thursday, two northern towns were bombed by the same two warplanes. On Friday, the government bombed three other rebel-held towns, according to a spokesman for the U.N. mission in Ivory Coast, and on Saturday struck three towns with MiG-24 helicopter gunships.