The troops were killed on Monday and yesterday ''during a joint reconnaissance mission with the Afghan national army'', Mr Sarkozy said.

''Serious measures, notably in the air, were taken to support and extricate our men caught in an extremely violent ambush.''

Mr Sarkozy would travel to Afghanistan to show his support for French troops there.

The latest casualties bring to 24 the number of French troops killed in action or in accidents in Afghanistan since French soldiers were first sent there in 2002.

It was the deadliest incident for international soldiers in post-Taliban Afghanistan, excluding helicopter or plane crashes. Nine soldiers from the United States were killed in an attack on a base in the north-eastern Kunar province on July 13.

The ambush was also the deadliest for the French army since a 1983 bombing in Lebanon in which 58 French parachutists died.

Military officials in Kabul said the clashes started with an attack on a NATO-led International Security Assistance Force patrol in the Sarobi district, about 50km east of the capital.

Afghan Defence Ministry spokesman General Mohammad Zahir Azimi said 13 rebels, including a Pakistani national, were also killed in the clashes.

In eastern Afghanistan, dozens of Taliban fighters and suicide bombers attacked a US military base early on Tuesday and at least 13 were killed, some in their own suicide blasts, Afghan officials said.

NATO's International Security Assistance Force said Camp Salerno, about 30km from the border with Pakistan, had been attacked but could give few details.

An officer in the force's media office said, ''We have heard about suicide bombers on foot. They are receiving indirect fire.''

He said fighting was continuing.

A suicide car bomb at the camp on Monday killed 10 Afghan labourers.

General Zahir said 15 terrorists also attacked the base early yesterday.

''Our commando units were deployed into the area and engaged the attackers and pushed them back.

''So far 13 attackers have been killed. Six blew themselves up, six others died in the explosions and one died in gunfire from commandos. Their bodies have been recovered.''

Six Afghan commandos had been wounded, he said.

The Taliban were driven from power in a US-led invasion in late 2001 because they would not hand over their al-Qaeda allies wanted in connection with the September 11 attacks on the US.

However, they regrouped, with some of them taking refuge in Pakistan, to launch an insurgency that military officials said was attracting more Arab, Pakistani and other Muslim fighters.

Violence has escalated into the northern summer,

Military officials said violence rose by 50 per cent this year compared with last year in some parts of the country. AFP