Large cranes and bulldozers tried on Saturday to lift the last remaining coach that rescuers have not reached yet among the strewn and mangled wreckage of three trains that rammed into each other in rapid sequence in Odisha's Balasore district, officials said.

The accident Friday night killed at least 261 people and injured more than 900, in one of the worst railway tragedies of the country.

Officials said this coach was buried in the ground as another passenger wagon jumped rail on top of it, the death toll is expected to jump once this wagon is brought up.

"Only one bogie is left, which is severely damaged. National Disaster Response Force (NDRF), Orissa Disaster Rapid Action Force (ODRAF) and Fire Service are still working to cut the bogie and try to recover the living or the dead," Odisha chief secretary PK Jena told Newspersons here Saturday.

"The death toll in the Balasore train accident has risen to 261," said South East Railway spokesperson Aditya Chowdhury on Saturday, adding that "rescue of injured passengers has been completed".

Other officials said work on the last passenger wagon was the only work left, other than removing the debris and clearing tracks for operations.

Some 200 ambulances, 50 buses and 45 mobile health units were working at the accident site, besides 1,200 personnel to rush the injured to hospitals.

Air force has sent two rescue helicopters with medical teams to evacuate critically injured passengers, officials said.

The train crash, the fourth deadliest in India according to available records, happened near the Bahanaga Bazar station in Balasore district, about 250 km south of Kolkata and 170 km north of Bhubaneswar, around 7 pm on Friday, prompting the Railway Ministry to order a probe.

The inquiry into the train accident will be led by A M Chowdhary, Commissioner Railway Safety, South East Circle, the Indian Railways said in a statement. The Commissioner Railway Safety comes under the Ministry of Civil Aviation.

While it is not clear what caused the crash, sources indicate a possible signalling failure.

The triple pile up occurred in a matter of just few minutes at around 7 pm.

The 12841 Shalimar-Chennai Central Coromandel Express derailed at Bahanaga Bazar between Balasore and Soro stations at around 7 pm, according to South Eastern Railway officials.

Almost immediately after this the 12864 Bengaluru-Howrah Superfast Express, derailed at the same site.

Some coaches of the Shalimar-Chennai Express fell on top of a stationary goods train in an adjacent railway track.

Railway Spokesperson Amitabh Sharma told PTI Video that the Coromandel Express derailed first, and its 10-12 coaches fell on the line on which the Bengaluru-Howrah Express was travelling, forcing it to jump off the tracks.

The various versions of the accident could not immediately be reconciled.

The opposition, while condoling the deaths which occurred in one of India's worst train disasters, also lashed out at the government.

"Government concentrates only on luxury trains. Trains and tracks of common people are neglected. Odisha deaths are the result of it. Rail minister should resign," CPI MP Binoy Viswam said in a tweet.

Gas cutters were used to extricate the bodies from under the derailed coaches.

From a vantage point high above, the accident site looked like as if a powerful whirlwind had thrown train coaches on top of each other.

Closer to the ground, mangled steel and bloodied and disfigured bodies lay enmeshed with each other creating a grotesque sight.

"Some of the scenes at the site were too gory to describe," said a passenger.

Railway tracks were almost destroyed at the spot as mangled coaches lay strewn all over, with some having mounted on another, while a few coaches turned turtle due to the impact.

Pijush Poddar, a resident of Berhampore in West Bengal's Murshidabad district, was travelling to Tamil Nadu in the Coromandel Express to join work there when the accident happened.

"We were jolted and suddenly saw the train bogie turn on one side. Many of us were thrown out of the compartment by the momentum of the derailment. When we managed to crawl out, we found bodies lying all around," he said.

Locals said they heard consecutive loud sounds, following which they rushed to the spot and found the derailed coaches, which were nothing but "a mangled heap of steel".

"The local people really went out on a limb to help us... They not only helped in pulling out people but retrieved our luggage and got us water, " Rupam Banerjee, one of the passengers, told reporters.

One of the coaches “was pushed into the ground " as another from a neighbouring train collapsed on top of it, passengers said.

Work is on to try and extricate that particular coach and retrieve the dead in it. Balasore district hospital looked like a war zone with the injured lying on stretchers in the corridor and rooms bursting at its seams with extra beds propped up.

Harried medical staff were seen trying to bring succour to patients many of whom are from states other than Odisha and had difficulties in communicating. In all some 526 railway accident victims have been admitted to this one single hospital.

Policemen and locals have been volunteering to donate blood at this and many hospitals through the night, said officials. More than 2,000 people gathered at the Balasore Medical College and Hospital in the night to help the injured, and many also donated blood, officials said.

The morgue at the hospital was a pile of white shrouded bodies, many of them yet to be identified as relatives are yet to make their way to the town with many train services cancelled or delayed due to the accident on a major railway trunk route.

Odisha Chief Minister Naveen Patnaik declared one-day state mourning on Saturday in the wake of the deadly triple train crash.

State Special Relief Commissioner Satyabrata Sahoo said those injured in the accident were undergoing treatment in different hospitals.

All government and private hospitals in the nearby districts, including the AIIMS at Bhubaneswar are being used.

Railway Minister Ashwini Vaishnaw reached the site in the morning as did Odisha chief minister Naveen Patnaik.

The railways announced an ex-gratia of Rs 10 lakh for the next of kin of the deceased, Rs 2 lakh for those grievously injured and Rs 50,000 for those who got minor injuries.

Prime Minister Narendra Modi too expressed his distress over the accident, and announced an additional ex-gratia of Rs 2 lakh for the next of kin of the deceased and Rs 50,000 for the injured from the PM's National Relief Fund (PMNRF).

The Odisha government issued helpline 06782-262286. The railway helplines are 033-26382217 (Howrah), 8972073925 (Kharagpur), 8249591559 (Balasore) and 044- 25330952 (Chennai).

Railway Minister Ashwini Vaishnaw, Chief Ministers of Odisha and Bengal Naveen Patnaik and Mamata Banerjee respectively were among those who were at the site Saturday morning to check on relief and rescue efforts.