Three trains have crashed in India’s eastern Odisha state, killing at least 288 people in the country’s worst rail disaster in 20 years.

Nearly 900 people were injured in the accident in Balasore district, said Pradeep Jena, the state’s top administrative official. The cause of the horrific crash on Friday evening was under investigation.

Rescue operations had concluded after an extensive search and recovery operation, involving hundreds of fire department personnel, police officers and sniffer dogs as well as the army personnel. National Disaster Response Force teams were also involved in the rescue work.

Officials said 1,200 rescuers worked with 115 ambulances, 50 buses and 45 mobile health units through the night at the accident site.

The accident, which happened about 200km (125 miles) from state capital Bhubaneswar on Friday night, led to chaotic scenes as rescuers climbed atop the wrecked trains to break open doors and windows using cutting torches to free survivors.

Sudhanshu Sarangi, director of Odisha’s fire department, said it was possible that people were stuck underneath but that it was unlikely they would still be alive.

“By 10pm (on Friday) we were able to rescue the survivors. After that it was about picking up dead bodies,” he said. “This is very, very tragic. I have never seen anything like this in my career.”

Ten to 12 coaches of one train derailed, and debris from some of the mangled coaches fell onto a nearby track, said Amitabh Sharma, a railroad ministry spokesperson.

The debris was hit by another passenger train coming from the opposite direction, causing up to three coaches of the second train to also derail, he added.

A third train carrying freight was also involved, the Press Trust of India reported, but there was no immediate confirmation of that from railroad authorities. PTI said some of the derailed passenger coaches hit cars from the freight train.

Dozens of bodies, covered by white sheets, lay on the ground near the train tracks as locals and rescuers raced to help survivors.

Scores of people also showed up at a local hospital to donate blood.

Saturday was declared a day of mourning in Odisha as the state’s chief minister, Naveen Patnaik, visited the district to meet injured passengers.