The incident took place near the town of Nawabshah in the southern Sindh province, officials have said.

The Hazara Express was travelling from Karachi to Rawalpindi when its 10 carriages went off the track, they added.

Railway minister Khawaja Saad Rafique said: "Ambulances are rushing towards the scene.

"An emergency has been declared at the Nawab Shah and Sukkur hospitals."

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Train crashes in Pakistan are relatively common, with a lack of modernisation on the colonial-era communications and signal systems, diminishing safety standards.

Traffic on the railway was halted so repairs could be made.