Seventy-five more Afghan forces were wounded in the violence.
Taliban clashed with Afghan forces in 14 provinces of the country over the past one week. More than 250 Taliban militants were also killed.
On Thursday, Afghan Acting Defense Minister Asadullah Khalid said that the Taliban have stepped up violence to gain leverage at the negotiation table.
According to UN figures, violence in Afghanistan in the last five weeks has been the highest in the last five years, EU special envoy Rolad Kobia said on Friday.