Mohammad Khan, deputy police chief in Uruzgan province, said a villager in the Bagh Char area of Khas Uruzgan district spotted the bodies in a field and called police.
"They were killed because the Taliban said they were spying for the government, working for the government," he said.
Special Report: Afghanistan
The acting Uruzgan governor, Khudia Rahim, said five or six of the 11 victims had been beheaded.
Meanwhile, NATO reported that a U.S. service member was killed in an insurgent attack Friday in eastern Afghanistan and another American died following a roadside bombing in southern Afghanistan on Thursday. NATO did not provide the exact location of the attacks.
A third service member died in an explosion Friday in southern Afghanistan, NATO said. The U.S. command said he was American.
Their deaths brought to 83 the number of international service members killed so far in June, which is already the deadliest month of the nearly 9-year-old war. At least 49 were Americans.
Also in the south, a joint force of Afghan and international troops killed a midlevel Taliban commander and other insurgents Thursday who were planting a roadside bomb near the provincial capital of Kandahar province, NATO said. Some of the insurgents were killed by a coalition airstrike, NATO said.
It said the Taliban commander, Faizullah, was responsible for roadside bomb attacks in the Arghandab district of Kandahar and is believed to have killed at least one coalition soldier in March.
The coalition is ramping up security in and around Kandahar, the largest city in the south, in an effort to drive out insurgents and bring the area under the control of the central Afghan government in Kabul.
In Khost province, another joint force captured an alleged operative of the Haqqani network, an al Qaeda-linked arm of the Taliban. Afghan and international forces have been involved in intense engagements with the Haqqani network along the border of Khost and Paktia provinces. Several insurgent commanders have been killed during operations, NATO said.