A suicide bomber blew himself up outside a NATO base in Afghanistan on Wednesday, killing at least two Afghan civilians and wounding several foreign and local troops, NATO said. It was the latest attack on an international military base in Afghanistan, where a Taliban insurgency is escalating. A man detonated an explosives-filled vest among a group of civilian truck drivers outside Camp Bastion, a major British base in southern Helmand province, NATO's International Security Assistance Force (ISAF) said. "At least two Afghan civilians were killed, and several ISAF personnel and Afghan civilians were injured when a suicide bomber detonated an explosive vest near the entrance to Camp Bastion," it said in a statement. "The number of civilians killed and wounded is not confirmed as the investigation continues," it added.