A roadside bomb that struck a civilian farm tractor has killed four people in southern Afghanistan, as AP reported. An Associated Press reporter in Kandahar province's Maruf district saw the bodies of three women and one man killed by the bomb Wednesday night. Three others were wounded in the blast. Provincial police chief Gen. Abdul Raziq says Afghan army and police officers are fighting insurgents across province, having killed 16 fighters and capturing 17 alive with bombs and assault rifles. Meanwhile, the governor's office in Helmand province says an airstrike Wednesday killed two Taliban fighters and a senior commander in Sangin district.