Suspected Taleban rebels have killed seven policemen and abducted two others in southern Afghanistan, officials say.
The police were fired at on their way to Kandahar, the local governor said.
In nearby Uruzgan province, militants beheaded two civilians. Four rebels were killed in a clash with US and Afghan forces, the US military said.
In Paktia, US forces also killed an Afghan soldier who shot at them. More than 1,400 people have died in violence in Afghanistan this year.
Two US soldiers received minor injuries when the Afghan soldier opened fire on them at a base near the northern town of Gardez, a US military spokesman said.
There was also heavy fighting overnight between suspected Taleban members and US forces in Kunar province near the Pakistan border, local authorities said.
The attack on the police convoy, in which two vehicles were reportedly destroyed by rockets, took place on Wednesday.
It was the latest in a series to target the country's fledgling police force.
The Taleban have increased attacks in recent months
"Seven police were killed on the spot and two are missing," Governor Mohammad Khan told the AFP news agency.
A spokesman for the Taleban, Qari Yousuf, said they carried out the attack.
It was not clear if the clash in Uruzgan's Deh Rawood district, which the US said left four militants dead, was linked to the ambush in Kandahar province.
The civilians were abducted on Monday from a village in another part of the province of Uruzgan and their bodies found two days later, Governor Jan Mohammed Khan said.
The rebels mistakenly thought they were working as interpreters for the US-led coalition forces, the governor told the Associated Press news agency.
Security forces raided a rebel camp in the area and made two arrests, he added.
Eastern and southern Afghanistan has been the scene of increasing attacks by insurgents in recent months.
The death toll so far this year is the highest since US-led forces drove the Taleban from power in late 2001.