A series of avalanches around a mountain tunnel in Afghanistan has left at least 28 people killed and hundreds more stranded, officials have said.

Some 70 people have been injured, and officials fear the number of casualties could rise further.

Afghan officials say some of the victims froze to death in cars or were overcome by exhaust fumes in the Salang Tunnel.

The tunnel is the main route from the Afghan capital, Kabul, to the northern city of Mazar-e-Sharif.

Relief teams are still trying to clear the route near the tunnel, they added.

Officials say that a blizzard struck the busy road on Monday, leading to an avalanche that buried people in their vehicles.