Rebel forces in Ivory Coast have accused the army of launching an attack on a cocoa town in the west of the country.

Western rebel leader Sergeant Felix Doh said their positions near Toulepleu, close to the border with Liberia, were attacked on Friday morning.

The fighting comes a day after he accused the army of attacking them in the south-west town of Grabo with helicopter gunships, killing 15 civilians and "some" rebels.

Less than a week ago, President Laurent Gbagbo pledged to observe a ceasefire and ground helicopter gunships ahead of peace talks in Paris planned for next week.

"It would be better to stop the negotiations and go on fighting because Gbagbo is not respecting the ceasefire," Sergeant Doh told the BBC.

An army spokesman has confirmed clashes east of Toulepleu and admitted that government troops are "engaged in operations" in the south-west but has blamed rebels for starting the fighting.

Truce

Troops from former colonial power France are monitoring the ceasefire but clashed recently with Mr Doh's forces in the west.

The rebels want to overthrow President Gbagbo

France said the latest fighting showed the urgent need of a ceasefire that would apply everywhere in Ivory Coast.

Sergeant Doh said the Movement for Justice and Peace (MJP) rebels would consider pulling out of the talks, but would wait to see the reaction of negotiators and the French.

On Wednesday, they had said they would sign the ceasefire and attend peace talks in Paris, after meeting the French ambassador.

The main rebel Ivory Coast Patriotic Movement (MPCI) signed a ceasefire in October but fighting resumed in the west a month later when new rebel groups emerged.

The MPCI has controlled the largely Muslim north of the world's biggest cocoa producer since 19 September.

Earlier, the United States dismissed proposals to put peacekeeping operations in the volatile Ivory Coast under United Nations control.

West African leaders drew up the plan earlier this week in the hope of restoring order to the country, wracked by violence since a rebel uprising began against the government in September.

But US State Department spokesman Richard Boucher said Washington did not believe a UN force was "appropriate" at this time.