A car bomb has exploded in Afghanistan's second-largest city, Kandahar, killing at least one person and wounding at least 14 others.

Local authorities say Monday's car bomb appeared to target Kandahar's police chief, Abdul Razaq, who was driving by in his car at the time of the attack. He escaped unhurt.

The attack comes after officials in southern Afghanistan said Taliban insurgents beheaded 17 Afghan civilians, including two women. Afghanistan's Interior Ministry says the civilians were killed late Sunday in the Kajaki district of Helmand province.

There are conflicting reports about the reasons for the killings. Earlier, Afghan officials said the Taliban attacked a late-night party because insurgents disapprove of music and dancing. But Helmand's governor said the killings followed a long-standing feud between two Taliban commanders over the two women.

A Taliban spokesman denied the group was involved in the attack, which Afghan President Hamid Karzai called an “unforgivable crime.”

NATO and the European Union also condemned the killings.

Officials also say insurgents overran an Afghan military post, killing 10 Afghan troops Sunday in Helmand's Washir district. A local official said five other Afghan soldiers either were kidnapped or joined the attackers.

In eastern Afghanistan, NATO officials say an Afghan soldier turned his weapon on two American servicemen, killing them. NATO troops returned fire, killing the soldier.

Monday's attack brings the number of foreign soldiers killed in such violence this month to 12. This year, 42 international troops have been killed in at least 33 insider attacks.

On Monday, NATO spokesman Brigadier General Gunter Katz said such attacks will not lead to less cooperation between the coalition troops and their Afghan counterparts. He told reporters in Kabul, “we are not going to reduce the close relationship with our Afghan partners.”