French troop reinforcements and helicopters touched down in Ivory Coast on Sunday to protect Westerners in the former French colony, as a showdown loomed between loyalists and forces behind the West African nation's bloodiest-ever military uprising.

Fears grew of wider conflict splitting West Africa's onetime economic powerhouse, as thousands of angry civilians in the second-largest city, Bouake, marched in support of coup forces who have seized that city, and one other in Ivory Coast's predominantly Muslim north.

"We are armed to the teeth, and there is no going back," a rebel commander known by the nom de guerre Samsara 110 declared in the rebel-held city of Korhogo.

Late Sunday, shooting was heard in Bouake, but it died down after about 30 minutes. Residents were on edge, waiting for a government assault that President Laurent Gbagbo's government has pledged since Saturday would be imminent.

Worried residents of Bouake included about 100 American children, ranging in age from infants to 12-year-old school children, who attend a boarding school in the city. The children are the sons and daughters of missionaries working across West Africa.

Ivory Coast's north-south, Muslim-Christian divides have widened dangerously since Thursday's failed coup. It was launched by insurgents who apparently included a core group of 700-800 ex-soldiers angry over their recent purge from the army for suspected disloyalty.

The uprising left at least 270 dead, by government count in the rebellion's first days. The dead included a Cabinet minister and former military ruler, Gen. Robert Guei, accused by the government of having sparked the coup attempt -- a contention denied by the rebels.

Defeated in Abidjan and two other cities, coup forces have dug in the north, base of support for opposition leader Alassane Dramane Ouattara.

Since Ivory Coast's first-ever coup shattered the peace in 1999, ethnic, political and religious tensions have regularly exploded between the mainly Christian south and west and Muslim northerners. Hundreds have died, including scores in an October 2001 massacre of Muslim Ouattara supporters in Abidjan widely blamed on the Gbagbo-loyalist paramilitary police.

Rifts likewise have widened in the country's security branches since the 1999 coup, often along political, ethnic or regional lines, and apparently lead to the recent army purge.

Late Sunday, a convoy of French troops headed north from Ivory Coast's commercial capital, Abidjan, ready to move out to protect French and international citizens in Bouake, 60 miles away, a spokesman for the French military base in Abidjan said.

French transport helicopters and a reported 100 extra French troops landed in Abidjan, the commercial capital, in the early hours Sunday, reinforcing approximately 600 troops already based there.

France said it deployed the reinforcements to protect the nation's 20,000 French citizens and others in the international community. Ivory Coast denied asking for French help putting down the uprising.

In Paris, Gbagbo spokesman Toussaint Alain blamed the uprising on Ivory Coast's neighbors -- an accusation widely believed aimed at the Muslim nation of Burkina Faso, on Ivory Coast's northern border.

Alain called the insurgents "pseudo-rebels" and "dogs of war, mercenaries ... paid by foreigners."

The presidential spokesman said that the government had proof that the rebels were using "foreign equipment" and receiving supplies by air.

Ivory Coast previously has accused Burkina Faso of providing haven and support to armed Ivorian dissidents.

Burkina Faso has beefed security along its borders with hundreds of troops since Thursday's uprising. Liberia, to the west, also has said it had reinforced its borders.

Since Friday, government convoys have been rolling north to the central capital, Yamoussoukro, gearing up to retake the rebel enclaves to the north.

There were claims from non-government sources this weekend that rebels had newly captured at least three other towns near the Burkina Faso border to keep their airstrips out of the hands of Ivory Coast loyalists. Those claims could not be independently verified.

In Korhogo, rebel commander Samsara 110 claimed insurgents had 1,000 rebels in Bouake, 780 in Korhogo and more hiding in Abidjan, ready for action.

With supplies including seized weapons from captured government garrisons, "We have the maximum of material," Samsara said -- bazookas, rocket and grenade launchers, and other heavy arms.

Loyalists, meanwhile, claimed Sunday to have surrounded Bouake. Only the desire to spare lives has staved off immediate attack there, one senior Ivory Coast military source claimed in an interview with The Associated Press.

In Abidjan, meanwhile, the Red Cross and other international organizations sought shelter for what it said were 3,871 people displaced by the coup violence in Ivory Coast's commercial capital.

Hundreds lost their homes on Friday and Saturday when paramilitary police burned a mostly Muslim shantytown near their base.

While the French deployment stood to help Europeans and the nation's large Lebanese community, danger was greater for hundreds of thousands of Muslim immigrant workers from surrounding countries.

The U.S. Embassy said it had no immediate evacuation plans for its nationals in Ivory Coast, the world's largest cocoa producer, and for calm decades past a base for multinational firms in West Africa.