PARIS, OCT. 6 -- For the second time this year, the dispatch to an African country of French foreign legionnaires, ostensibly to protect French lives, appears to have saved a pro-French regime under threat of collapse.

A week after Ugandan-based rebels stormed into northern Rwanda and fought their way near the seat of power, the government of President Juvenal Habyarimana appeared today to have restored calm to the capital, Kigali. Fighting, however, was reported to be raging in the north.

Diplomats reported that the presence of 300 French troops, along with 600 Belgian paratroops and 500 soldiers from neighboring Zaire, seemed to have thwarted a potential assault on the capital. Skirmishing in Kigali ceased today, and a U.S. Embassy spokesman said the French and Belgian forces had "made a tremendous difference." A news service said legionnaires encountered "armed elements" of rebels on Friday and had been "obliged to riposte."

Today, while Rwandan troops conducted house-to-house searches for weapons in the capital, arresting several people, the foreign troops assisted government soldiers in patrolling Kigali's streets, reportedly deserted.

An Air France jumbo jet arrived in Paris today with more than 140 foreigners, including 96 French citizens, who had been trapped by the fighting. News services from Kigali and Nairobi reported that another Air France jet, a Boeing 747, was headed for Djibouti and Paris today, and that about 170 Belgians were expected to arrive tonight in Brussels aboard a Sabena DC-10. Lufthansa was scheduled to evacuate Germans wanting to leave Rwanda, and the Soviet Union announced that unspecified measures were being taken to "ensure the safety and the evacuation of the families of Soviet personnel."

Before the invasion, France had about 670 citizens living in Rwanda, a former Belgian colony. There also were more than 1,600 Belgians, about 400 Germans and 250 Americans, including tourists, in Rwanda when fighting broke out.

French Prime Minister Michel Rocard has emphasized that the sole mission of the latest French force sent to Africa was to ensure the safe evacuation of foreigners. But the intervention seemed likely to set off a new debate about France's military role in Africa, following other recent ventures in Chad and Gabon.

Last May, hundreds of French troops were sent to Gabon when an outbreak of civil protests threatened to topple President Omar Bongo's government. The demonstrations quickly halted after the arrival of the French forces, who did not even have to fire a shot.

In Chad, French forces have periodically intervened to prevent Col. Moammar Gadhafi, the radical leader of neighboring Libya, from installing surrogate forces in power. France still maintains thousands of troops at bases in Chad, the Central African Republic and Djibouti to permit rapid deployment to areas of turmoil.

Sensitive to its reputation as "the gendarme of Africa," France has sought to distance itself from employing force merely to prop up regimes for the sake of serving its own interests. Since President Francois Mitterrand took office in 1981, France has insisted that it would only intervene when its foreign nationals are directly threatened by turmoil in Africa.

In the past, French public opinion rarely questioned involvement of French troops, largely because such incursions were conducted mostly by foreign legionnaires, the famed volunteer force comprising outcasts from other countries. French interventions in Africa have generally been short-lived, involving little loss of French lives.

But lately, political surveys have shown growing public dismay with the high economic cost of buttressing governments in former African colonies.

In contrast, public opinion in France has strongly supported Mitterrand's assertive policy in the Persian Gulf, where 13,000 French troops and a dozen warships are poised to prevent further aggression by Iraq and to enforce the U.N. trade embargo against Baghdad. To the anguish of his political opponents, Mitterrand's approval rating has soared more than 10 points since the gulf crisis to 66 percent, reversing a steady slide in popularity polls earlier this year.