Rebels pressed deeper into Ivory Coast's western cocoa growing region as the West African country's embattled government urged young men to mobilize en masse to fight an increasingly complex civil war. The emergence of new rebel factions in the west of the world's largest cocoa producer has aggravated the creeping chaos in a country of 16 million that was already split in two after a failed coup in mid-September.

Hundreds died in four weeks of fighting after the attempted putsch. Hundreds more were killed in battles in the west over the past week between rebels fighting to topple President Laurent Gbagbo and loyalist troops backed by mercenaries.

Soldiers from former colonial power France said western factions had advanced 75 miles east from the Liberian border to reach the town of Guiglo on Saturday.

"The loyalists are still holding out in Guiglo," said a French army spokesman. French soldiers are evacuating foreigners caught in fighting and also monitoring a truce signed by the main rebel group.

Being pushed to Guiglo is a reverse for loyalist forces -- backed by helicopter gunships -- who said last week they were near to driving that group of rebels from the country. The rebels have hundreds of Liberian fighters with them.

Advancing as far as Guiglo also takes the rebels deeper into one of the most important cocoa growing regions in a country producing some 40 percent of the world's supply of the beans used to make chocolate.

MOBILISATION URGED

In Abidjan, Defense Minister Kadet Bertin urged men aged 22 to 26 to volunteer for the war front en masse.

"We are calling for the mobilization because with the increase in the number of fronts, we also need to increase the size of the security and defense forces," he said.

The discovery of a mass grave by French troops on Thursday has added to increasing evidence of atrocities, but the government said it had nothing to do with the grave found behind rebel lines and was ready for a foreign inquiry.

Gbagbo's adviser in Europe said he believed the grave had been set up by the rebels to tarnish the government's name.

Foreign media quoted villagers as backing the version of the Patriotic Movement of Ivory Coast (MPCI) rebels that the grave contained the bodies of more than 100 people -- most of them immigrants killed in a raid by Gbagbo's forces.

Gbagbo's supporters accuse immigrants, who make up a quarter of Ivory Coast's 16 million population, of aiding rebels whose roots lie largely in the opposition stronghold of the largely Muslim north.

The MPCI said it was filing a complaint to the International Court of Justice over the killings and also threatened to withdraw from peace talks in Togo if West African mediators did not condemn the deaths in strong enough terms.

Talks between the main rebel group and government negotiators have yielded little after well over a month.

PHOTO CAPTION

Crack French soldiers man a makeshift roadblock 60 kms west of Daloa December 7, 2002. The French troops are in the country to evacuate any foreign nationals caught in fighting and to monitor a ceasefire line as Ivory Coast's army battles rebel soldiers in the west of the former French colony. REUTERS/Luc Gnago