At least 45 people were killed when explosives used in road works caught fire and detonated in a northern Pakistan village, causing several homes to collapse, police and witnesses said. Police said an electric short circuit triggered a pre-dawn fire in a house in Gayal village, 168 kilometers south of Gilgit, which spread to a nearby building where the explosives were being stored. Some 200 people rushed to extinguish the blaze and while they were fighting the fire, the explosives -- owned by a government contractor building roads -- caught fire and exploded, witnesses said. An official at the police emergency centre in Gilgit said 45 people had been killed. "The final toll may exceed (this)," he said. Provincial chief secretary Mohammad Saeed Khan told AFP that "41 people died on the spot." "Another 13 are missing," he said adding that at least 63 people had been admitted to hospitals in the nearby Diamer and Chilas valleys. Witnesses said weeping and wailing residents desperately sifted through the debris in search of missing people. Police and paramilitary troops were engaged in rescue operations. The authorities also sent military helicopters to move the injured to hospitals. Hospitals officials said they had already received 45 bodies. "At least 28 people are in critical condition," doctor Mohammad Ashraf of Chilas hospital told AFP by telephone. "The blast was massive, it triggered panic among the rescue workers (putting out the fire)," said a resident Abdul Bar, who lost his cousin in the explosion. Another witness, Jumma Khan, said the casualties were high because several houses had collapsed after the blast. "Many people were buried inside the demolished houses," he said. Houses in the village, which is located in a narrow valley and has a population of 3,000 people, are mostly built with mud and stones and have wooden roofs. The casualties included women and children, a police officer said without giving a break down of the victims. Local officials said the contractor, Mohammad Waris, had intended to use the explosive to blast rocks in a road-building project in the mountainous region. "He was granted a contract to build a link road in the area," an official said. Prime Minister Zafarullah Jamali expressed "deep grief" over the loss of life and ordered an investigation, officials said. Residents said a mass funeral was scheduled in Gayal late Sunday for more than 40 of the victims. **PHOTO CAPTION*** At least 45 people were killed when road works explosives caught fire and detonated in a village in northern Pakistan, according to police. (AFP/File/John MacDougall)