Media playback is unsupported on your device Media caption Footage from James Dunning shows the extent of the crash in the foggy conditions

At least three people have been killed and 25 injured in a pile-up involving almost 100 vehicles in the US state of Virginia, police say.

They said there were 17 separate crashes within a distance of one mile (1.6km) on Interstate 77 near the base of Fancy Gap Mountain.

The accidents began shortly after 13:00 local time (17:00 GMT) on Sunday, when there was heavy fog in the area.

It was reportedly the most deadly of several similar pile-ups since 1997.

Queues of traffic in southbound lanes near the scene of the crashes stretched for eight miles, police said.

"This mountain is notorious for fog banks," said Glen Sage of the American Red Cross office in the town of Galax.

"They have advance signs warning people. But the problem is, people are seeing well and suddenly they're in a fog bank."

At the centre of the crash was an eight-car wreck. Some of them were on fire, police spokeswoman Corinne Geller said.

Nina Rose, 20, was driving to New York state with her mother when she passed the crash scene.

"We just saw a bunch of people standing on the median, just with their kids and families all together. There were cars smashed into other cars, and cars just underneath other semi-trucks," she said.

Photos from the scene showed a charred tractor-trailer and other burned-out cars. School buses were used to take stranded travellers to shelters and hotels.

There have been six similar incidents since 1997, but Sunday's incident was the most deadly, the Roanoke Times newspaper reported.