NEW DELHI • At least 27 people were killed after two packed trains derailed while crossing a bridge hit by floods in central India overnight, the authorities said, highlighting again safety problems with the nation's crumbling railway network.

Rescuers searched in darkness for passengers feared trapped on the trains that were travelling in opposite directions when some of their carriages derailed in Madhya Pradesh state, the officials said.

The trains derailed within minutes of each other near the town of Harda at about 11.30pm on Tuesday.

"There have been 27 deaths due to the accidents," Madhya Pradesh railway police chief M. S. Gupta said yesterday. "All the coaches have been cleared and all bodies have been collected from inside," he said, adding that the death toll could still rise slightly.

Roughly 300 people were rescued after about 10 of the trains' carriages derailed, officials said.

A passenger described how water poured into the carriages in the minutes after the accident.

"Water filled the coach till here," the unnamed man told a regional TV station, gesturing to his waist. Another said there was "a sudden jerk and the carriage broke and people were crushed under that".

Television footage showed carriages lying on their sides in a field of mud.

Another 25 people have been injured and taken to hospital, a second official said, adding that the carriages have not fallen into the river.

One of the trains was on its way to Mumbai when the accident happened, while the other was travelling in the opposite direction, the Press Trust of India (PTI) news agency reported.

It was not clear how many passengers the trains were carrying.

The Kamayani Express travelling from the financial city of Mumbai appeared to have been hit by a sudden surge of water on the swollen Machak river, derailing the last four to five carriages, Railway Ministry spokesman Anil Saxena told Indian television.

The Janata Express, travelling to Mumbai from the eastern city of Patna, was also hit by the water, with the engine and the first two to three carriages derailing, he said.

"There is some suggestion of flash floods on the tracks that caved the tracks," Mr Saxena said of the first train.

Monsoon rains have hit large swathes of the country in recent weeks, flooding rivers and roads and claiming some 180 lives in mainly western and eastern India.

Police and doctors have been deployed to the accident site, with television footage showing medical supplies being piled on a nearby station platform and rescuers combing through tilted carriages.

"Rescue operations are in full swing. Things are under control and most of the people have been rescued," Mr Saxena told the NDTV network.

But rescuers said operations were being hampered by flooding in the area and officers were working through the night mostly in darkness.

"The entire area has been reeling under heavy rainfall for the last few days. The roads are badly damaged, even the access road," Mr Saxena said.

Railway Minister Suresh Prabhu said on Twitter: "Rushing emergency medical and other relief personnel to spot, darkness, water creating hurdles but ordered all possible help. Trying our best."

PTI reported that the river below the bridge crossing had been swollen and there had been water on the tracks.

India's railway network, one of the world's largest, is still the main form of long-distance travel in the vast country, but it is poorly funded and deadly accidents are frequent.

Last year, train wrecks killed more than 25,000 people, which critics blame on India's overloaded and outdated railway network.

Prime Minister Narendra Modi pledged this year to massively increase railway spending.

The government said it would invest US$137 billion (S$189 billion) to modernise India's crumbling railways over five years.

AGENCE FRANCE-PRESSE, REUTERS