US forces "mistakenly" killed seven Afghan policemen and injured five in Nangarhar province of eastern Afghanistan, an official said on Tuesday.
US troops opened fire and dropped bombs on a police post in Khogyani district on Monday night, a police officer in the district Nasiz Ahmad said, adding three police vehicles were also damaged.
Ahmad said the bodies were still lying unburied, adding those responsible should be brought to justice.
Local officials said apparently there was a misunderstanding in the incident.
Meanwhile, the US-led coalition forces said in a statement that some coalition soldiers were conducting a patrol in the district when they were suddenly ambushed.
The forces requested air support, which killed seven Afghans of unconfirmed identities, according to the statement.
About 13,000 coalition troops are being deployed in Afghanistan to hunt down militants and keep security.