Youths loyal to Ivory Coast President Laurent Gbagbo blocked roads in the main city Abidjan on Wednesday (July 19) to protest against an identity scheme, police said, in the latest challenge to a U.N.-backed peace process. Witnesses said some of the pro-Gbagbo militants, known as Young Patriots, burned tyres and carried sticks and rocks to force drivers to turn back. There were reports of barricades in two provincial towns and the western cocoa port town San Pedro. The scheme, part of a struggling plan to reunite the war-divided West African state and hold elections by end-October, 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 -- administered by a rebel-nominated minister in a unity government -- arguing that pro-opposition foreigners may fraudulently gain nationality and voting rights. The consulate of former colonial power France, which has 4,000 troops in Ivory Coast helping more than 7,000 U.N. peacekeepers, said there were some 40 barricades in all and reiterated its consular advice against unnecessary travel. The world's top cocoa grower has been divided in two since a brief 2002-2003 civil war in which rebels who tried to oust Gbagbo seized the north. Gbagbo's government controls the south. Several cocoa exporters said they had closed warehouses in Abidjan and staff stayed at home. A Reuters reporter saw little sign of activity at Abidjan's port and a shipper said warehouses were also closed in San Pedro.