At least seven people were killed, 40 others were injured in avalanches and hundreds were stranded at a snow-blocked mountain pass in northern Afghanistan, officials said Tuesday.

The avalanches took place Monday afternoon on Salang road after heavy snows, at 3,300 metres where passes through a five-kilometer tunnel and links capital Kabul to the northern region.

Rescuers worked throughout the night and pulled out dozens of survivors buried under thick blanket of snow, Afghan defence ministry spokesman General Zahir Azimi said.

At least seven people were killed by avalanches or froze to death and up to 40 others were injured since the snowstorm began Monday morning, said General Kabir Adarabi, the police chief of northern province of Baghlan.

'Around 100 vehicles are still trapped in the snow-blocked road near the main tunnel but the strong snowstorm in the area hampers the rescuing teams' advance,' he said.

Soldiers and police were mobilized to join other rescue workers, Azimi said, adding that army helicopters, ambulances and bulldozers were rushed to the area.