At least two people were killed and 30 injured when six carriages of a Pakistani passenger train derailed on Sunday and plunged into a ravine.
Troops were working under searchlights to reach passengers trapped in the wreckage of the train travelling from Rawalpindi, a city adjoining the capital Islamabad, to the eastern city of Lahore.
A railways minister said up to 400 passengers could have been on the derailed carriages.