Human Rights Watch said the promised amnesty has not stopped local commanders from retaliating against former members of the army, police and intelligence services.
The insurgents have taken 18 of the country’s 34 provincial capitals in recent days, including its second- and third-largest cities, Herat and Kandahar.
A deadly suicide car bombing Sunday came after the Taliban agreed on Friday to halt its attacks in Afghanistan's Helmand province on condition the U.S. stop airstrikes in the area.
The Taliban pledge came after a meeting with U.S. peace envoy Zalmay Khalilzad and Gen. Austin Miller, commander of U.S. troops in Afghanistan, a Taliban figure familiar with the discussions said.