Youths loyal to Ivory Coast President Laurent Gbagbo blocked roads in the main city Abidjan on Wednesday to protest against an identity scheme for elections due by end-October, police and witnesses said.

The scheme, part of a U.N.-backed peace plan in the war-divided West African state, aims to issue identity papers to around 3.5 million people who are not legally registered.

But the country's ruling party has vowed to block the process, arguing that pro-opposition foreigners may fraudulently gain nationality and voting rights.

"Since 0630 (GMT) this morning there are Young Patriot barricades on some roads in (southern, central and northern) parts of the city," one military police officer told Reuters.

"They are blocking the roads with anything they can find," he said, adding the police had not received instructions to intervene.

Witnesses said some of the pro-Gbagbo militants known as Young Patriots were setting fire to tyres on roads and carrying sticks and rocks to force drivers to turn back.

Ivory Coast has been divided in two since a brief 2002-2003 civil war in which rebels who tried to oust Gbagbo seized its northern half, while the government controls the south of the world's leading cocoa producer.

There was no immediate reports that the latest protests had any impact on cocoa shipments.

A U.N.-backed peace process which foresees elections by the end of October has been mired by deadlock as the factions bicker over details.

The pro-Gbagbo Young Patriots -- a group notorious for anti-French rioting in November 2004 -- also rioted for several days in January, attacking the bases of the U.N. peacekeeping mission in the government south with petrol bombs and rocks.