A crowded Pakistani passenger train rammed into another at a station yesterday and a third train ploughed into the wreckage, killing 128 people and injuring 170, officials said.
In all, almost 2,000 people were aboard the trains, a railway official said, many of them asleep at the time of the pre-dawn disaster.
Officials said the driver of one of the trains had apparently missed a signal to stop, setting the disaster in motion.
"I was sleeping. I woke up at the noise of a huge bang and then there was a big jerk and smoke all over the place," said a distraught injured passenger, Mohammad Amin.
"There was total darkness ... I hit the floor and fainted," said Amin, who was desperately searching for his son.
The Karachi Express, coming from the eastern city of Lahore, rammed into the rear of the Quetta Express, which had stopped at a station near Ghotki town for repairs, police said.
A third train, coming the other way from the port city of Karachi, then ploughed into three derailed carriages that had spilled across the track, police said.
Ghotki, in southern Sindh province, is 430km (270 miles) northeast of Karachi. A Reuters photographer said he saw about 50 blood-soaked bodies lying near the crash site while many injured were being treated nearby.
Three compartments were completely crushed and two cranes had been brought in to hoist the compacted wreckage apart as police and rescue workers searched for bodies.
In all, 128 people were killed and 170 injured, 12 of them critically, said Ishaq Khan Khakwani, state minister for railways. "All bodies have been removed from the site and sent to mortuaries and hospitals," he told Reuters.
President Pervez Musharraf, who visited the crash scene, ruled out sabotage.
"It's clear that it was not sabotage; rather, in my view, it might be carelessness," he told state-run television.
Pakistan Railways officials pointed the finger of blame at the driver of the train that rammed the stationary one.
"The driver of the Karachi Express violated the signal and the accident apparently happened because of his mistake," the chairman of Pakistan Railways, Shakeel Durrani, told reporters.
Senior railway official Junaid Qureshi agreed. "He either ignored the red signal or he was snoozing," Mr Qureshi said, referring to the driver, who he said was among the dead.
Debris, including luggage from smashed compartments, was scattered across a wide area as rescuers picked their way through twisted piles of metal and wood. Passengers, some of them injured, could also be seen searching for missing friends and relatives.
A military spokesman said troops and helicopters were helping get the injured to hospital.
In Pakistan's worst train crash, in 1990, 307 people were killed when a packed passenger train smashed into a freight train, also in Sindh province. A train crash in Punjab province in 1997 killed 136.