Fifteen civilians travelling in a bus in western Afghanistan were killed by "anti-government gunmen," a provincial official said Friday.They were stopped by the gunmen late Thursday on the way to Laal district, said Abdul Hai Khatibi, spokesman for the Ghor provincial governor."The gunmen dragged the passengers out of the bus and shot them in the heads and chests," Khatibi told dpa, adding that one man managed to escape in the dark."The dead are 11 men, three women and one child."He did not know if the driver was among those shot.The Taliban, often blamed for such attacks on civilians, have not commented.Earlier Thursday two Finnish women working for the International Assistance Mission (IAM) were shot dead in the adjacent province of Herat.The security situation in Afghanistan has worsened as the Taliban militants continue their summer offensive.