Here are the latest developments:
Six coaches of the Kamayani Express running from Mumbai to Varanasi derailed at around 11:30 pm while crossing a culvert near the Machak river close to Harda, about 160 kilometres from state capital Bhopal. (Pics)
Minutes later, an engine and four coaches of the Janata Express, going to Mumbai from Jabalpur, derailed. Among those who have died are 10 women and five children, the Madhya Pradesh government said.
"I am going to the accident site, will talk after taking stock of the situation," said Madhya Pradesh Chief Minister Shivraj Singh Chouhan.
A railway official said water flooding the tracks entered the derailed coaches. Earlier reports had said that the coaches fell into the river.
Railways Minister Suresh Prabhu, in a statement in the Rajya Sabha today, said that a flash flood caused the swollen Machak river to overflow and wash out a section of the rail tracks, leading to the derailment of the two trains.
Even 10 minutes before the accident, Railways Board Chairman AK Mittal said, the tracks were intact and many trains had passed safely.
People who live near the accident site played a big role in rescue efforts in the middle of the night, with rescue teams delayed because heavy rain and flooding had damaged roads.
A senior official said at about 7.30 am, most of the people trapped in the derailed coaches had been rescued. The unaffected coaches of the two trains were detached and moved to Itarsi. Three special trains took doctors and rescue teams to the accident site. (Track updates)
A 35-member team of the National Disaster Response Force or NDRF has been dispatched with equipment like gas cutters from Bhopal to rescue any people who may still be trapped on the derailed coaches.
"The two train accidents in Madhya Pradesh are deeply distressing. Deeply pained over the loss of lives. Condolences to families of deceased," tweeted Prime Minister Narendra Modi.