Six private security guards have been beheaded during a bank robbery in Afghanistan.

No one immediately claimed responsibility for the attack, but it fits the pattern of recent Taliban attacks against high-profile government and military targets.

The victims - believed to be Afghans - were poisoned before being killed at a branch of Kabul Bank in the northern city of Mazar-e-Sharif.

Police spokesman Sherjan Durani said someone had apparently mixed the poison into the guards' food the night before.

Mr Durani says the robbers took about £170,000 in US and Afghan currency after beheading the guards.

The killings came as insurgents launched a rocket and suicide bomb attack on NATO's largest base in the south of the country.

One foreign soldier and two civilians were wounded in an initial rocket attack on Kandahar airfield.

Two suicide bombers then detonated explosives strapped to their bodies outside the base perimeter.

The assault lasted about an hour before the attackers fled.