Explosions rocked the southern Abidjan suburb of Koumassi overnight and yesterday, as fighting between insurgents seeking to oust Ivory Coast's Laurent Gbagbo and security forces spread to new areas of the main city.

Security in the world's top cocoa grower is deteriorating, with gun battles between rival forces most of last week and hostilities resuming across a north-south ceasefire line that had been largely quiet since a 2002-3 war ended in stalemate.

Ivory Coast has been in turmoil since a disputed November election between Gbagbo and his rival Alassane Ouattara, who won the poll according to UN-certified results that Gbabgo has refused to concede.

Fighting has mostly been restricted to northern proOuattara suburb of Abobo, where an insurgent force calling itself the invisible commandos has seized control of most of the territory and forced out pro-Gbagbo security forces.

Gunfire has also been heard much closer to the central business district. Across the other side of town, residents of Koumassi said fierce fighting had flared up there too.

"Since last night there have been a lot of military on the streets. They said they are looking for insurgents who have infiltrated the neighbourhood," said student Eloise Kouassi. "The traffic is dead: everyone is staying in."