At least one person was killed and 30 others injured when several coaches of the Lahore-bound Karachi Express derailed between Mando Dero and Sanghi railway stations near Rohri late on Saturday night, district and rescue officials said.

Railways officials said that all people travelling on the train have been rescued and work is now being carried out to clear the railway tracks.

"Railways staff have temporarily cleared the Down track and train operations have resumed on it. Now, work is being done on the Up track. It can take several hours," an official told Dawn.com.

The deceased woman has been identified as a resident of Landhi in Karachi, Sukkur Commissioner Shafiq Ahmed Mahesar confirmed to the media. He added that 15 of the injured passengers had been discharged from the taluka hospital in Rohri.

According to initial reports, the 15-Up Karachi Express departed Rohri junction around 1:15am. When the train reached near Sanghi nine of its bogies, including AC and Economy class coaches, derailed with a big bang.

As most of the passengers were asleep, the sudden accident caused panic among them. Rescue work was started by passengers on a self-help basis. However, soon Edhi ambulances arrived at the scene of the accident and shifted the injured to the taluka hospital in Rohri and Sukkur Civil Hospital.

It was not immediately clear what caused the derailment but railway officials said that an inquiry is underway.

It was also not immediately clear how many passengers were on the train.

Trains including Green Line, Sir Syed, Rehman Baba and Shah Hussain would face a delay of seven to eight hours as they are still halted in the Sukkur division. Their actual and correct arrival time in Karachi would be assessed once they leave the Sukkur division and enter the Karachi division which starts from Tando Adam railway station in Sanghar.

Meanwhile, Pakistan Railways General Manager Nisar Memon surveyed the accident site, saying the investigation will be carried out as soon as possible to ascertain the cause of derailment. He added that the train was fitted with the latest engine, which tracks the speed and other details of the journey at every moment. "We will review the data from the engine's log to aid us in the investigation," he told the media.

Railway Minister Azam Swati told a local channel that the accident was being investigated and the government would provide financial compensation to the heirs of the deceased woman and all the injured.

Additional input from the Associated Press and Mohammad Hussain Khan in Hyderabad.