MAZAR-I-SHARIF, Afghanistan: Five civilians were killed on Friday when their vehicle hit a mine in northern Afghanistan, where a Taliban insurgency has increasingly encroached in recent years, police said.

The device exploded Faryab province's Qaysar district, police spokesman Sayed Massoud Yaqoubi told AFP.

“Five civilians were killed as their vehicle was hit by a roadside mine in the Shakh area of Qaysar district,” Yaqoubi said.

The spokesman accused the Taliban, who have been waging a bloody insurgency against Afghan government and US-led Nato troops, of planting the bomb.

The militant group was not immediately reachable for comment.

The attack comes two days after a suicide bomber killed four people in Afghanistan's northern capital, Mazar-i-Sharif, where Nato troops are due to hand over security responsibility to Afghan forces on Saturday.

The town will become the fifth area of the country to transition to local security control this week as part of a process that critics have branded too much too soon, with question marks looming over Afghan security capabilities.

Civilians are the biggest casualties in the near 10-year war in Afghanistan, where 150,000 foreign forces are stationed.

The United Nations has said that more than 1,400 civilians have been killed in the first six months of 2011, blaming insurgents for 80 percent of civilian deaths.