A express train has ploughed into the back of another train in northern India, killing up to 15 people and trapping as many as 50 passengers in the wreckage. The CNN-IBN channel, quoting a local senior superintendent of police, said 15 bodies had been pulled from the site of the crash on tracks outside the town of Mathura, 150 kilometres (93 miles) south of New Delhi. Other reports said four people had died. Vijay Kumar, another senior police official in the nearby town of Agra, home to the Taj Mahal, told the channel that the crash happened at 5:30 am local time (0000 GMT), but declined to give figures for dead or injured. He said the Goa Express had run into the back of a stationary train outside Mathura station. Rescuers were using mechanical cutters to cut through the bars on the windows of the badly crushed last carriage of the stationary train to reach people feared trapped inside. The NDTV news channel put the death toll at 10-12, with 40-50 feared trapped. CNN-IBN also reported up to 50 trapped. "There are many people who are injured and many people who are dead," an unnamed eyewitness told CNN-IBN. "A lot of people fell onto the tracks because of the impact of the collision." Ten of the injured had been taken to a nearby hospital.