Sapper Collins was based at Aldershot

The attack took place at 1915 local time on Sunday, as Sapper Collins drove with a colleague along the main road towards Skopje from the airport.

A group of youths threw the projectile which shattered the windscreen and struck the soldier on the head.

The vehicle crashed and Sapper Collins was taken first to a US military hospital in nearby Kosovo, and then to the university hospital in Skopje.

He underwent surgery but later died from his injuries, despite the efforts of doctors.

Investigation

Nato issued a statement on Monday confirming the attack, which it condemned as "disgraceful".

Sapper Collins came to this country as part of a Nato force to help in a mission of peace and such appalling incidents are simply unacceptable

Brigadier Barney White-Spunner

It said: "A piece of concrete or similar object came through the windscreen and hit a soldier on the head.

"He was treated at a military medical unit and transferred to the neurological unit at Skopje hospital and unfortunately died at 4.20 this [Monday] am.

"The army's Special Investigations Branch is currently co-operating with local Macedonian police."

The statement added that the other soldier riding in the vehicle was not injured.

An MoD spokesman said the vehicle - believed to be a marked Land Rover - was travelling alone on a military route.

He said it was not yet known if the youths involved were Macedonian or Albanian.

Weapons handover to include:

Two tanks Two armoured personnel carriers Six anti-tank weapons 130 mortars and 210 machine guns

Prime Minister Tony Blair, currently on holiday in France, spoke by telephone to Macedonia's president Boris Trajkovski about the incident.

Downing Street said Mr Blair emphasised the importance on investigating the soldier's death and bringing those responsible to justice.

President Trajkovski expressed his deep condolences and committed his government to bringing those responsible to justice.

Both leaders reiterated the importance of completing the weapons operation and of developing the political progress.

Nato spokesman Major Neal Peckham said the attack was one of a number of incidents in which Nato vehicles had been attacked by youths.

But he said the "regrettable" incident would not affect the resolve of the task force to complete its mission.

Sapper Collins, from Sheffield, was single and had been based at Aldershot in Hampshire, the MoD said.

Brigadier Barney White-Spunner, the task force commander, said: "The thoughts of every member of the Brigade are with Ian Collins' family and friends at this terrible time.

"Sapper Collins came to this country as part of a Nato force to help in a mission of peace and such appalling incidents are simply unacceptable."

'Important step'

Monday is the first day of Nato's 30-day Operation Essential Harvest in Macedonia.

Rapid mobile units on the ground, including specials forces from several Nato armies backed up by close air support, are expected to be involved.

Some 1,500 British troops are already on the ground, and a further 400 could be deployed, according to the MoD.

Nato commanders insist the mission will result in a meaningful reduction in weapons and is an important step towards disbanding the guerrillas.

However, nationalist elements within the Macedonian Government have dismissed Nato's planned collection of 3,300 weapons, alleging that the rebels possess an arsenal of at least 70,000 arms.

Royal Engineers have been at the forefront of recent Nato operations.

One of their soldiers was killed in Bosnia in 1999, and they were one of the first units to go into Kosovo.