A car bomb has exploded near a farmers' market in southern Afghanistan, killing eight people and wounding 17.

The provincial police chief Mohammad Hussein Andiwal told reporters there were no security forces in the area and that civilians were the target. He said the bombing took place in the Gereshk district of Helmand province.

The police chief blamed the Taliban for the blast, and the French news agency reported the Taliban claimed responsibility in a phone call to the agency.

Monday, police said, Taliban insurgents ambushed a police patrol in Herat province, killing four policemen and two civilians.

Also Monday, the Afghan defense ministry said soldiers killed a number of Taliban militants in southern Zabul province.

A resurgent Taliban movement has vowed to step up its violent campaign against Afghan, NATO and U.S. soldiers in Afghanistan.

Some information for this report was provided by AFP and AP.