A helicopter belonging to the NAT0- led International Security Assistance Force (ISAF) crashed late Thursday in southern Afghanistan's Zabul province, killing four foreign soldiers on board, a provincial government spokesman said Friday.

Jan Rasouli told Xinhua by telephone that the incident took place in Nawkhil village, which is close to the provincial capital Qalat.

The spokesman said that the crash was possibly caused by technical problems.

The ISAF confirmed the crash but refused to provide more information noting that the incident was under investigation.

Taliban spokesman Qari Yusuf Ahmedi told reporters by telephone from unknown location that the insurgent group had shot down the helicopter around midnight killing 25 Afghan and foreign soldiers on board.

NATO has planned to launch a massive offensive against the Taliban militants in neighboring Kandahar province later this year.