Army columns were rushed in and Air Force helicopters deployed for relief and rescue operations for passengers injured in the triple train crash site at Bahana Nagar in Odisha, a Defence official said on Saturday.
The operations are being carried out in coordination with the railway authorities on the ground, he said.
"Army medical and engineering teams with ambulances and support services have been deployed from Eastern Command," he said.
Army columns, including engineering and medical personnel, have been rushed to the accident site from its installations at Barrackpore and Panagarh in West Bengal to the rail disaster site, the official said.
Two Mi17s were deployed for evacuation of the injured passengers, he said.
The accident, one of the deadliest in the country, has claimed 261 lives, railway official said.
It took place in Balasore district about 250 km south of Kolkata and 170 km north of Bhubaneswar around 7 pm on Friday.
Three trains - the Bengaluru-Howrah Superfast Express, Shalimar-Chennai Central Coromandel Express and a goods train were involved in the accident.