By the CNN Wire Staff

A helicopter from NATO's peacekeeping mission in Afghanistan crashed late Thursday in the southern provice of Helmand, killing six members of the force, allied military spokesmen reported.

There was no enemy activity in the area when the helicopter went down in Helmand Province, said Col. Gary Kolb, a spokesman for NATO's International Security Assistance Force. The crash happened around midnight Kabul time (2:30 p.m. ET), Kolb said.

The fatalities were reported in an ISAF statement, which noted that the cause of the crash was still under investigation. Another ISAF spokesman, Capt. Justin Brockhoff, said neither the number or nationalities of those on board had been confirmed.

-CNN's Barbara Starr, Mitra Mobasherat and Adam Levine contributed to this report.