At least 26 people were killed and 50 injured on Saturday night when nine coaches of a passenger train derailed in eastern India, in the latest disaster to hit the vast and accident-prone state railways, police said.

The express train from Jagdalpur to Bhubaneswar derailed near Kuneri station, in the state of Andhra Pradesh, around 30 km (18 miles) outside the town of Raigarh.

"Nine bogies were derailed of which three have turned and fallen off the track," said local Superintendent of Police L.K.V. Ranga Rao. "Most of the casualties and deaths are from the three sleeper-class compartments."

No evidence of sabotage has been detected, Rao said, adding the cause of the derailment appeared to be a technical fault. Rescue operations were under way and coaches that had not derailed had been towed from the scene.

India's state railways, built during British colonial rule, have an appalling safety record - the result of decades of underinvestment and a priority on keeping fares low for the 23 million passengers who use the network every day.

In the last serious accident, 150 people died when a train derailed late last year in the northern state of Uttar Pradesh. India recorded 27,581 railway deaths in 2014, the most recent year for which figures are available, with most victims falling from, or being struck by, moving trains.

"Anguished to learn about the train accident near Vizianagaram," Andhra Pradesh Chief Minister Chandrababu Naidu said on Twitter, offering his condolences to the families of the victims. "We are investigating the reason for accident."

Prime Minister Narendra Modi also tweeted that the tragedy was "saddening" and said the railways ministry was working to ensure quick relief and rescue operations.