Suicide raid killed American soldier on Kabul base: U.S

KABUL (Reuters) - An explosion which killed an American and an Afghan soldier on an army base in Kabul this week was carried out by a suicide bomber, the U.S. military has confirmed, the second time in five months an insurgent has managed to infiltrate a base.

On Monday, NATO said one of its service members had died and several had been wounded in an explosion on an Afghan army base in the capital but gave no details. One Afghan soldier was also killed in the blast and three were wounded.

Taliban spokesman Zabiullah Mujahid said the attack was carried out by a Taliban infiltrator, who struck while foreign advisors were training Afghan troops.

The U.S. Defence Department has now confirmed it was a suicide attack.

"Sergeant Robert J. Barrett, 20, of Fall River, Massachusetts, died April 19 in Kabul, Afghanistan, of injuries sustained when a suicide bomber attacked his unit," the department said in a statement.

NATO efforts to train Afghan forces have been plagued in recent months by rogue Afghan soldiers and police turning weapons on their trainers, and infiltrators gaining access to compounds meant to be secure.

The latest attack is the second in recent months in which an insurgent has managed to penetrate a military base and kill foreigners.

In December, a Jordanian infiltrator at a U.S. base killed seven employees or contractors working for the CIA and a Jordanian intelligence officer. In November, an Afghan police trainee killed five British soldiers at a checkpoint.

The attack happened on an Afghan military base near Kabul's airport, a combined civil-military facility which in the past has come under rocket attack as well as suicide strikes at its gates.

Last year was the deadliest for foreign forces in Afghanistan since the Taliban were overthrown in late 2001. A total of 520 troops, more than 300 of them American, died in 2009, according to icasualties.org, an independent website that monitors foreign troop deaths in Iraq and Afghanistan.

The first three months of this year have also seen a rise in troop deaths. Seventy-eight foreign troops died in the first three months of 2009, compared to 139 for the same period this year.

There are around 125,000 foreign troops in Afghanistan, more than half of them American, and that figure is set to rise to around 150,000 by the year's end.

(Editing by Angus MacSwan)