PARIS, SEPT. 7 -- French forces firing a U.S.-made Hawk missile shot down a long-range Libyan bomber over Ndjamena, the capital city of Chad, in a new escalation of the war in that country today.

The Libyan embassy in Paris said the military action had brought France into "direct confrontation" with Libya.

The downed aircraft, a Soviet-made Tupolev 22, was one of two Libyan bombers dispatched to attack Ndjamena in retaliation for the Chadian Army's destruction of a Libyan air base at Matan as Sarra in southeastern Libya. The base, more than 60 miles north of the contested Chadian-Libyan border, was captured Saturday night in the first attack inside Libya by Chadian President Hissene Habre's forces, which have French and U.S. backing.

Habre's government in Ndjamena announced that Libyan bombers also carried out retaliatory attacks today against a new French-built airstrip at Abeche, about 400 miles to the northeast near the border with Sudan.

Chadian officials said five bombs were dropped, killing two civilians. Reports from Chad said French Mirage F1 fighters took off from their base in the capital shortly after that attack, but there was no known engagement with Libyan planes.

The Libyan embassy in Paris reacted to the French role with a sharply worded statement. It said, "France is from now on implicated in a direct confrontation with Libya. Libya has shown self-control and tried to avoid a confrontation, but France has grasped neither the extent of the danger nor its evolution."

France, which strongly supports Habre, has maintained troops, warplanes and antiaircraft defenses in Chad for some time to protect the southern half of the country against Libyan attacks and to give logistics support to Habre's Army. The French presence there rose to more than 2,000 men during a series of attacks last spring, but has since dropped back to about 1,500.

Although French planes have bombed Libyan installations in northern Chad on several occasions, French antiaircraft defenses had not destroyed a Libyan plane before today's downing of the supersonic Tupolev 22. The second Libyan plane over Ndjamena was fired on but not hit, French officials reported, and neither attacker was able to drop its bombs on the airport, the main base for French warplanes in Chad.

The official Libyan news agency, JANA, reported another version of the engagement. It said:

"The Libyan Air Force launched successful air raids on the military air base of Abeche and on Ndjamena airport following its transformation into a military base receiving continuous U.S.-Israeli reinforcements.

"One of our planes was hit. French aircraft and French and U.S. missiles, manned by Americans and French, took part in an attempt to resist the attack by our planes, which were able to hit their designated targets with precision."

Libyan radio later today warned civilians and diplomats to leave Ndjamena, implying more retaliatory air raids are planned despite the French defenses. The broadcasts underlined the danger of increased military involvement facing France, which already has committed an aircraft carrier group and two minesweepers to the Persian Gulf.

Observers here pointed out that Libya's leader, Col. Moammar Gadhafi, has been accused of organizing terror attacks against European targets in past disputes.

The Libyan ambassador to France, Hamed Houderi, said in a television interview here that "those who put oil on the fire also are in danger of getting burned." His statement fit into a series of Libyan charges that France and the United States have incited Habre to carry on his conflict with Gadhafi and supplied him with the equipment to make it possible.

"When one furnishes the equipment, the logistics, the intelligence, this is very important," Houderi said.

France and the United States have provided critically important weapons and training for Habre's army, particularly France's Milan antitank missiles. Both countries have denied, however, that their personnel have participated in Chadian attacks.

Foreign Minister Jean-Bernard Raimond and Defense Minister Andre Giraud said specifically today that France was not behind Saturday's attack inside Libya.

"We want no Franco-Libyan confrontation, and the risks of confrontation between Libya and France can only come from Libyan interventions, particularly bombings inside Chadian territory," Giraud said.

French officials have frequently expressed reservations about Habre's resolve to reconquer the contested Aozou strip separating Chad and Libya. After a series of French-assisted Chadian victories this spring drove Libyan forces from Chad proper, Paris advised Habre to leave the dispute over the Aozou strip to mediation by the Organization of African Unity or some other international agency.

There have been reports that the Aozou area contains rich uranium deposits, but these have never been confirmed. The dispute reflects chiefly national and ethnic rivalry between Chad and Libya.

Habre's forces, disregarding French advice, on Aug. 8 seized the town of Aozou, the area's main settlement, which had been occupied by Libya since 1973.

In Habre's first major reversal this year, however, Libyan troops retook the town last week, giving a boost to Gadhafi's declining prestige.