KABUL, Aug. 21 (Xinhuanet) -- Four US soldiers were killed and three others injured in a roadside bomb explosion in southern Afghanistan on Sunday, a US military statement said.

   The soldiers were patrolling in Daychopan district of Zabul province when the bomb exploded. They had been conducting offensive operations in support of an ongoing mission to search and defeat Taliban remnants in the area, according to the statement.

   The injured were sent to a nearby base for treatment and were said to be in stable condition. Enditem