A roadside bomb killed four U.S. troops Tuesday in southern Afghanistan -- the year's deadliest single attack on international forces. An Afghan civilian working with the Americans also died.

The Americans were patrolling with Afghan soldiers when their vehicle struck a bomb , the U.S. military said in a statement that omitted identities of the dead and the attack's location pending notification of relatives.

Twenty-nine U.S. military personnel have died in Afghanistan this year, far surpassing the eight Americans killed in the first two months of 2008. The Obama administration is sending 17,000 more troops to Afghanistan starting in the spring.

TALIBAN EXTENDS SWAT VALLEY TRUCE

Taliban militants in Pakistan's Swat Valley extended a cease-fire declared on Feb. 15 "for an indefinite period," spokesman Muslim Khan said. He said he expected Pakistan's military to follow suit.

The military did not immediately comment on the announcement. It has been observing the cease-fire but has said it will not withdraw from the valley until there is lasting peace. Last week, the government agreed to the introduction of Islamic law in the region.

FRENCH COURT THROWS OUT DETAINEE CASES

A Paris appeals court overturned the terrorism convictions of five former detainees at Guantanamo Bay, ruling that French police agents were out of line in questioning them at the U.S. prison camp in Cuba.

The appeals court ruled that agents from the French counterterrorism agency DST who questioned the five inmates at Guantanamo in 2002 and 2004 had overstepped their roles.

ASSOCIATED PRESS