A man in police uniform killed six Nato troops during a training session in Afghanistan on Monday, the US-led International Security Assistance Force (ISAF) said.
"An individual in an Afghan border police uniform turned his weapon against International Security Assistance Forces during a training mission today, killing six servicemembers in eastern Afghanistan," the statement said.
"The individual who fired on the ISAF forces was also killed in the incident. A joint Afghan and ISAF team is investigating this incident."
ISAF did not reveal the casualties' nationalities, in line with its policy.