At least 11 people have been killed and dozens more injured after two passenger trains collided in Pakistan's southern port city of Karachi early Thursday, hospital officials said.

"So far we can confirm 11 people dead from the train accident, and we have received 50 injured," Seemi Jamali, spokeswoman at Karachi's Jinnah Hospital told AFP, after one train rammed into the other while it was waiting at the city's Jumma Goth railway station.