GOMA, Zaire -- French marines and foreign legionnaires rolled into refugee camps in Rwanda on Friday trying to stem the ethnic slaughter that has horrified the world. They pledged not to pick a fight with rebel forces who view them as enemies. France says the operation, approved Wednesday by the United Nations, is strictly humanitarian. But the rebel Rwandan Patriotic Front is suspicious because French intervention blocked a rebel offensive in 1990. The commander of the small UN peacekeeping force in Rwanda said Thursday he hoped the French would stay away from front lines between troops of Rwanda's Hutu-dominated government and the mainly Tutsi rebel movement. Overnight, the rebels pressed heavy attacks inside Kigali, the capital. Red Cross officials said a hospital in central Kigali was hit by an artillery shell Friday during sporadic fighting, but there was no immediate word on casualties. Some 100 kilometers west of Kigali, a small group of French soldiers in armored vehicles met no opposition and was welcomed by residents Thursday after advancing several kilometers from the Zaire border, the French government said. A reconnaissance team of French marines moved into the northwestern region of Gisenyi, French state radio reported, quoting an unidentified government source. The Rwandan army is believed to control the western third of the small central African nation. The rebels have won control of the eastern two-thirds since the war resumed April 6 after a suspicious plane crash killed Rwanda's Hutu president, who had reached a power-sharing accord with the Tutsi minority. About 40 Foreign Legion paratroopers protected by helicopter gunships were the first troops to cross the border from Bukavu, 40 kilometers south of Goma, late Thursday, the French military said. The soldiers evaluated medical needs and conditions Friday at refugee camps around Cyangugu in a government-controlled region, the French military said. About 8,000 Tutsis are in the camps, and the French troops will try to prevent the widespread slaughter being inflicted on Tutsis by Hutu militias. The mission to an area where Tutsi refugees are in a majority was apparently intended to show that Paris' Operation Turquoise would be impartial despite France's past support of the Hutu government. The majority of refugees in the northwest as a whole are Hutu refugees. "The role is only to protect refugees," said Colonel Andre Schill, a French spokesman in Goma. He said French troops would use their weapons only to defend themselves or refugees. The United Nations and aid groups estimate that more than 200,000 Rwandans have been killed since the death of President Juvenal Habyariman. Most victims have been civilians who were massacred, but his death also rekindled a civil war that had been halted by a peace accord signed in August. The French government said it was sending about 2,500 soldiers and marines for the two-month mission authorized Wednesday by the UN Security Council as a stopgap until an all-African peacekeeping force twice that size can deploy. Schill said 500 French soldiers were in Goma by Thursday, including marine infantrymen, supply troops and combat engineers. About 250 paratroopers were in Bukavu, he said. In Kigali overnight, there was heavy rebel fire at Camp Kimihurura, the base of the Presidential Guard, and artillery units in the eastern part of the city. Rebels also attacked government positions to the north on the foothills of Mount Kigali. Major General Romeo Dallaire, the Canadian commander of the 450 UN peacekeepers in Kigali, spoke by telephone Thursday night with a senior French officer, an aide said Friday. The aide, Major Jean-Guy Plante, said Dallaire and the French officer made no firm plans for cooperation or coordination. "They had to talk just to touch base," he said. Earlier, Dallaire had cautioned against intervening in a civil war "when you do not have the consent of both sides." He said he took seriously rebel threats to attack French troops. About 10,000 chanting people marched through rebel-controlled parts of Kigali on Friday to protest the French operation. They carried banners reading "No to French imperialism," "We thank RPF" and "Let them go!", referring to the French troops.The rebels' representative in Paris, Jacques Bihozagara, said rebel forces would not seek out French troops. But he said the rebels would "treat them as invaders" if they did make contact.