By Saliou Samb

CONAKRY, March 10 (Reuters) - Police in Guinea fired in the air on Monday to disperse protesters rioting over higher petrol prices, just hours before a high-profile visit by French Foreign Minister Dominique de Villepin to the west African nation.

Villepin is on a whistle-stop tour to Angola, Cameroon and Guinea -- Africa's three temporary members of the United Nations Security Council -- to rally support for his country's stance against war in Iraq.

Guinea chairs the council this month and its vote could be vital to determine whether the United Nations sanctions war against Baghdad. Villepin was due in Conakry later on Monday.

Witnesses said hundreds of youths, including many school children, took to the streets in the poor suburbs of the capital Conakry in protest against a 23 percent rise in fuel prices announced by the government on Friday.

Police fired live bullets in the air and used teargas to disperse the demonstrators. Residents said some protesters had been arrested.

"We were in the middle of our class when the riots erupted," said a student at a high school in the teeming suburb of Matam.

"Some students clashed with the police. I climbed over the wall to escape," he said.

Youths have rioted repeatedly in dirt-poor Guinea over recent weeks to protest at the devastating power cuts and water shortages crippling the capital.

On Friday, the government announced the price of a litre of petrol would be raised to 1,600 Guinean francs from 1,300 to reflect a rise in oil prices due to the Iraqi crisis.

Guinea has been wooed by both the United States and its former colonial power France, the nation which is leading opposition to the war.

Guinea has so far refused to take a clear position, demanding that Iraq cooperate fully with the U.N. but at the same time declaring that force should be used only as a last resort. Villepin was due to meet with ailing President Lansana Conte, who has ruled the country with an iron fist since seizing power in a coup in 1984.

France is Guinea's biggest bilateral donor, although relations have been strained by its criticism of Conte's poor democratic record. The U.S. has strong ties with Guinea, which it sees as a buttress against regional anarchy, and has given Conte military support in recent years.

The U.S. State Department's top man for Africa, Walter Kansteiner, visited Guinea last month.