Thousands of young men have volunteered to fight on the side of the Ivorian Government against rebels who have taken control of the north of the country over the past three months.

The government's recruitment drive, scheduled to take place on Tuesday, was postponed to Thursday, because of the huge number of volunteers coming forward.

We want uniforms... We are ready to go to the front

Young volunteers

The authorities' recruitment effort comes as a truce and peace talks with the main rebel group are in jeopardy.

The rebels have threatened to walk out of the talks in Togo, following the discovery of a mass grave which they say government forces are responsible for.

Both sides have accused each other of preparing to resume fighting.

The United Kingdom has called on all its nationals in Ivory Coast to leave "immediately".

The BBC's Paul Welsh in Ivory Coast says all the ingredients are now present for a full-scale war.

Tough selection

The young men gathered outside the army headquarters in Abidjan on Tuesday morning, answering a call from the defence minister for men aged 20-26.

They chanted slogans such as "We want uniforms" and "My country will be the victor". They said they were prepared to sacrifice their lives for their country.

The volunteers say they are prepared to die

The government wants 3,000 volunteers to bolster its forces fighting two new rebel groups which have emerged in the past two weeks in the west of the country.

The new recruits will have to face selection tests, including running 5km in 25 minutes, before six weeks of training, instead of the usual three months.

"After six weeks, they will know how to fight, but they will not necessarily go to the front. That will depend on the situation," Lieutenant-Colonel Jules Yao Yao was quoted as saying.

'Maximum alert'

Our correspondent in Ivory Coast says the recruitment drive has made the main rebel group, the Patriotic Movement of Ivory Coast (MPCI), nervous.

The MPCI says President Laurent Gbagbo is preparing for all-out war.

It is threatening to pull out of peace talks because the Economic Community of West African States, which has been mediating between the two sides, has not publicly condemned what the rebels call a massacre of civilians.

"The MPCI troops are on maximum alert and ready to resume hostilities if nothing is clarified about the grave," the secretary general of the MPCI, Guillaume Soro, told the French news agency AFP.

Last week the French army, which has been monitoring the ceasefire, found a mass grave in the village of Monoko-Zohi, near Daloa.

Fellow villagers say 120 of their relatives were killed by government troops.

The government denies any responsibility, saying the rebels are to blame - the village is in rebel-held territory.

France on Tuesday called for an international investigation to establish who was responsible for the massacres and for those who carried them out to be put on trial.

"Impunity in Ivory Coast must come to an end," Foreign Ministry spokesman Francois Rivasseau said.

Stalled talks

The MPCI says that before leaving the talks it will hold discussions with the chief mediator, Togolese President Gnassingbe Eyadema.

On Monday, President Gbagbo and Mr Eyadema held talks, but did not reveal what they discussed.

Mr Gbagbo later told AFP that he would sign a "political document" on Wednesday with parties represented in parliament, but he did not give any details.

Gbagbo and Eyadema met on Monday

The United Kingdom has joined several other western countries in advising its citizens - about 500 of them - to leave Ivory Coast "while commercial air services are still available".

"This is a final warning. It may not be possible to arrange any subsequent evacuation by civil or military means," the British embassy in Abidjan said on Monday.

At least 400 people have been killed since the 19 September uprising by disgruntled soldiers, and hundreds of thousands displaced by the fighting.