At least 10 vehicles were involved in the main collision
Seven people have been injured, two of them seriously, in a multi-vehicle pile-up on a motorway in Greater Manchester.
At least 10 vehicles collided on the A627M, near Oldham, on Friday morning. Several minor collisions then happened behind the main crash.
It is thought the vehicles may have skidded on a patch of black ice.
The A627M was closed northbound between Broadway and Slattocks Link Road, along with a number of adjoining roads.
Drivers were being advised to find alternative routes as the roads could be closed for some time.
Greater Manchester Police said the first collision, involving about 10 vehicles, happened during the morning rush hour at about 0800 GMT.
"It is believed the cars involved may have skidded on a patch of black ice," a spokeswoman said.
"Two of the seven people injured are believed to have more serious injuries.
"A 46-year-old man suffered a broken leg and a 39-year-old woman suffered head and chest injuries."
One of the motorists involved, Karen Lewis, told the BBC she noticed ice in the road before her vehicle was suddenly hit from behind.
Describing the aftermath, she added: "At one point three lads had to run out of the way because a car was going to plough into them.
"A kind gentleman in a Costa van brought me across to the hard shoulder but unfortunately I didn't get his name - but thank-you very much whoever you are."