A suicide bomber wearing an explosive vest attacked a patrol of Western and Afghan troops in southern Afghanistan on Saturday, killing at least two civilians and wounding 21, district officials said. Abdul Qayum, governor of Sha Joy district in Zabul province, told Reuters the attacker struck as troops were patrolling a market in the district. Lieutenant-Commander Sam Truelove, press officer for U.S. and NATO-led forces in the capital Kabul, confirmed that there had been a blast but had no further details.