Afghan villagers discovered the beheaded bodies of six government contractors Sunday in the country's restive south, the apparent victims of insurgents who regularly target state projects, officials said.
Meanwhile, the death toll from a suicide car bombing at the site of a key national council in the capital, Kabul, rose to 12, officials said, as NATO said an international service member was killed by a roadside bomb.
Kandahar police spokesman Ahmed Durrani said villagers found the bodies. He said the men were involved in building police compounds and checkpoints in Kandahar, the birthplace of the Taliban.
There was no immediate claim of responsibility for the attack. The Taliban have previously targeted contractors, warning Afghans against working for the government.
The Taliban did, however, take credit for the blast Saturday outside the huge tent where the Loya Jirga consultative forum is to be held later this week in Kabul. Thousands of prominent Afghans are scheduled to meet there to debate a contentious security agreement with the United States.
Interior Ministry spokesman Sediq Sediqqi said three of the 12 dead were members of Afghanistan's National Security Force, with many of the rest civilians. The Taliban gave the bomber's name as Saeed Kabuli, but provided few other details.
Hours before the blast, President Hamid Karzai announced that U.S. and Afghan negotiators had completed a final draft of the Bilateral Security Agreement to be presented to the gathering for debate. If approved, it would allow U.S. troops to stay in Afghanistan after the final withdrawal of international combat forces in 2014.
Also Sunday, NATO said a service member was killed in the south. It did not announce the nationality of the service member killed, though most troops serving in southern Afghanistan are from Britain and the United States.
So far this year, 139 NATO service members have been killed in Afghanistan, according to an Associated Press count. This compares to 394 troops of the NATO-led coalition killed in 2012.
Meanwhile in northern Afghanistan, a suicide bomber attacked the deputy governor of Balkh province. While the official escaped unhurt, one civilian was killed, Balkh police spokesman Sher Jan Durrani said.