A Nato air strike in Afghanistan has killed four policemen and a civilian, officials say.
The air strike took place in the eastern Ghazni province, where Nato planes had been called in for support.
A spokesman for the provincial governor told the BBC the policemen were in civilian clothes and may have been mistaken for Taliban fighters.
Nato is investigating the incident. The death of civilians in air strikes has become a highly sensitive issue.
The latest incident happened after a Taliban attack on a local police post before dawn.
Nato planes were called in to help the local police, the AFP news agency quoted local officials as saying.
"They (Afghan Local Police ) were in civilian clothes - there were four of them, and they were towing a vehicle when the air strike hit them," said Fazul Sabawoon, a spokesman for Ghazni's governor.
"They could have been mistaken for Taliban."
Afghan President Hamid Karzai has been highly critical of Nato strikes causing civilian casualties in the past.
He banned Afghan security forces from calling in such strikes after an air strike killed 10 civilians in February. However it remains unclear whether the ban has been enforced.
Thursday's incident comes just one day after the Taliban attacked a courthouse in the western province of Farah, killing more than 50 people. The suicide bomb and gun attack also left a further 90 people, mostly civilians, injured.
Militants disguised as soldiers tried unsuccessfully to free suspected Taliban members. According to a local police chief, the aim of the attack had been to free 15 Taliban prisoners who were being transferred to the courthouse for trial.
The attack was the deadliest in Afghanistan since December 2011, when at least 70 people were killed in a blast at Kabul's Shia shrine.
The BBC's Bilal Sarwary in Kabul said the attack would further dent the confidence of the Afghan people in the ability of the national army to protect them, as foreign troops prepare to withdraw in 2014.
Coalition forces have been fighting the Taliban in Afghanistan for eleven years.
Some 100,000 foreign combat troops are scheduled to withdraw from Afghanistan by the end of next year.