Sweden is preparing to deploy a fleet of Boeing Vertol 107 helicopters to Afghanistan.

Four of the helicopters were recently modified with improved ballistic protection, machine guns, flight data recorders and the capability to allow crews to use night vision goggles.

Additional modifications due on the aircraft include installation of a defensive aids system, and sand filters for the engines to make them fly in the dusty environment.

Built by Kawasaki in Japan, the 13.90m-long Swedish military helicopter has a payload capacity of 9,700kg and a maximum flying speed of 280km/h.

The Swedish Armed Forces have a total of 14 Boeing Vertol 107 helicopters with nine based at Ronneby near Karlskrona and five at Linköping in the south of the country.