The railways on Sunday sought a CBI inquiry into the Balasore train crash, hours after minister Ashwini Vaishnaw said the "root cause" of the accident and the people behind the "criminal" act have been identified.

Railway officials also indicated that possible "sabotage" and tampering with the electronic interlocking system, which detects the presence of trains, led to the Friday accident.

However, several opposition parties stepped up pressure for Railway Minister Vaishnaw's resignation, with Congress president Mallikarjun Kharge calling for fixing accountability from top to bottom.

The BJP hit back, saying the track record of the Congress-led UPA government's railway ministers was nothing short of a disaster and they should not politicise the issue.

“We have recommended a CBI probe into the triple train accident,” Vaishnaw told reporters in Bhubaneswar on Sunday evening.

Earlier in the day, he said the cause of the accident was related to electric point machine and electronic interlocking.

"The setting of the point machine was changed. How and why it was done will be revealed in the probe report." "The root cause of the horrifying incident has been identified... I do not want to go into details. Let the report come out. I will just say that the root cause and the people responsible for the criminal act have been identified," he said.

The death toll in the three-train crash on Friday was revised to 275 from 288 by the Odisha government which said some bodies were counted twice earlier.

With 187 bodies yet to be identified, keeping them till the time they are claimed by the victims' kin is proving to be a challenge to the local administration.

While 110 bodies were being kept at the AIIMS Bhubaneswar, the remaining have been sent to Capital Hospital, Amri Hospital, Sum Hospital and some other private facilities.

Anxious relatives thronged the NOCCI Business Park to identify photos of passengers displayed by authorities.

Vaishnaw, who had been camping at the site of the train accident along with Union Minister Dharmendra Pradhan, said two railway tracks have been restored on the main trunk line connecting eastern and southern India and overhead electrification work has also started.

Officials said till the overhead electric cable is repaired, only diesel locomotives can be run and it may take another three days before electric trains can ply.

The ministers said restoration work was being carried out on a war footing and efforts were on to send people affected back home.

"By Tuesday we should be able to do it," Pradhan said.

The accident disrupted passenger and goods traffic between important industrial centres. Many of the patients initially admitted to Balasore and other local hospitals have been released or shifted to bigger cities with multi-speciality hospitals including Cuttack, Bhubaneswar and Calcutta.

The railways said 123 trains have been cancelled, 56 diverted, 10 short terminated, and 14 trains have been rescheduled for the period June 3-7.

Many of the passengers in the two trains were migrant workers. Railway spokesperson Amitabh Sharma said that even if the victims were ticketless travellers, they will receive compensation.

This is in line with a Supreme Court order, officials said.

So far, the railways has disbursed Rs 3.22 crore as ex-gratia in 285 cases -- 11 deaths, 50 grievous injuries and 224 minor injuries.

'Could be tampering or sabotage from within or outside'

Top railway officials, while explaining how the point machine and the interlocking system function, said the system is "error proof" and "fail safe" but did not rule out the possibility of outside intervention.

"It is called a fail-safe system, so it means that even if it fails, all the signals will turn red and all train operations will stop. Now, as the minister said there was a problem with the signalling system.

"It could be that someone has done some digging without seeing the cables. Running of any machine is prone to failures," Jaya Verma Sinha, Member of Operation and Business Development, Railway Board, said.

An electric point machine is a vital device for railway signalling for quick operation and locking of point switches and plays an important role in the safe running of trains. Failure of these machines severely affects train movement and deficiencies at the time of installation can result in unsafe conditions.

Railway officials virtually ruled out driver error and system malfunction and said there was "no question of over-speeding" by trains.

A senior railway official who did not want to be identified said, "It could be a case of tampering or sabotage from within or from outside. We have not ruled anything out." The crash involving Bengaluru-Howrah Superfast Express and Shalimar-Chennai Central Coromandel Express and a goods train occurred around 7 PM on Friday near the Bahanaga Bazar station in Balasore, about 250 km south of Kolkata and 170 km north of Bhubaneswar.

Why was CAG report ignored: Opposition parties

The Congress demanded the resignation of Railway Minister Ashwini Vaishnaw over the Odisha rail tragedy and attacked Prime Minister Narendra Modi.

Addressing a press conference at the AICC headquarters, Congress MP Shaktisinh Gohil and AICC's publicity and media department head Pawan Khera alleged that it was a "man-made devastation caused by utter negligence, serious lapses in the system, incompetence, and a narcissistic sense of know-it-all attitude of the Modi government".

The Opposition party also said that Modi should accept part of the responsibility for the "mess" that it alleged that his government has inflicted on the Indian Railways and the people.

"Unequivocally and unambiguously, we demand the resignation of the Union Railway Minister Ashwini Vaishnaw. Nothing short of it," Khera said.

In a series of tweets in Hindi, Kharge posed questions to the Modi government and alleged that "PR gimmicks" have made the working system of the dispensation "hollow".

The Parliamentary Standing Committee in its 323rd report criticised the Railways for the "disregard" shown by the Railway Board towards the recommendations of the Commission of Railway Safety (CRS), Kharge said.

"According to Comptroller and Auditor General, 79 per cent of funding was reduced in Rashtriya Rail Sanraksha Kosh (RRSK) when Rs 20,000 crore was to be made available every year. Why has there been a huge decline in the amount of track renewal works?" the Congress chief said.

Congress general secretary Priyanka Gandhi Vadra too called for the resignation of Vaishnaw.

The NCP also asked why the measures suggested in the 2022 Comptroller and Auditor General (CAG) report to prevent train disasters were not implemented by the Centre.

The party also alleged that CAG report stated that train accidents were waiting to happen due to several shortcomings, but the railway ministry and the minister failed to take this warning seriously.

Nationalist Congress Party (NCP) spokesperson Clyde Crasto asked if Vaishnaw had read the CAG report.

''If he did, then why was it not taken seriously and why were the suggestions of the CAG not put into implementation immediately?" he sought to know.

" Is this not enough reason for Ashwini Vaishnaw to tender his resignation," Crasto asked.

BJP IT department head Amit Malviya shared on Twitter what he said were the details of accidents under previous ministers and added such "worthies" are the ones demanding the resignation of the "most qualified" railway minister the country has had in seven and half decades.

"Stop politicising the unfortunate Balasore tragedy because the track record of railway ministers, under the UPA, to put it mildly, was nothing short of a disaster. Let us focus on relief and rescue operation and putting life and rail back on track, at the earliest," he said.

The TMC, CPI and RJD have also demanded the railway minister's resignation.

West Bengal Chief Minister Mamata Banerjee questioned the death figures.

"If from one state (West Bengal) , 182 are missing and 61 are confirmed dead, then where would the figures stand?" she asked, addressing a press conference at the state secretariat, Nabanna.

Stating that Duronto Express trains introduced during her tenure as the railway minister were "pushed out of priority", the TMC chief asked whether the engines of Vande Bharat Express trains introduced by the Modi government were up to the mark.

Many bodies remain unidentified

The Odisha government on Sunday revised the accident death toll to 275 from 288, and put the number of injured at 1,175.

Chief Secretary P K Jena told newspersons some bodies were counted twice.

"After detailed verification and a report by Balasore District Collector, the final toll has been fixed at 275," he said.

Jena said the injured are being treated in different hospitals in Soro, Balasore, Bhadrak and Cuttack.

"So far, 793 passengers have been discharged and 382 are being treated at government cost," he said.

A team of doctors and experts from the AIIMS-Delhi and other central hospitals in national cpital have been rushed to Bhubaneswar through a special IAF flight. Union Health Minister Mansukh Mandaviya is also in Odisha.

Jena said 88 bodies have been identified so far and 78 handed over to their families.

"It is a real challenge for us to preserve the bodies here as we have a facility to keep a maximum of 40 bodies," an official of AIIMS Bhubaneswar told PTI, adding that additional arrangements were made at the Anatomy department.

Admitting that identification was a major challenge for the administration as the victims hailed from different states, the chief secretary said the state government has uploaded the details of the passengers on three websites of the Special Relief Commissioner (SRC), Bhubaneswar Municipal Corporation (BMC) and Odisha State Disaster Management Authority (OSDMA).

Lists and photographs of deceased passengers are also uploaded on the websites to facilitate identification.

States trying to trace passengers

Of the 127 people hailing from Tamil Nadu who had reserved tickets for Coromandel Express, contact could not be established with eight people and the rest were safe, the state government said According to information received so far on the train accident, no person from Tamil Nadu was killed or injured warranting treatment, it said.

Exhausted and traumatised, 137 survivors arrived in Chennai on Sunday by a special train from Bhadrak.

Recalling the ordeal, Murugan said he and others could feel their coach tilting rapidly and falling on one side and many people were injured severely. "It was pitch dark, cries of people could be heard, many lay dead." The Andhra Pradesh government has identified that 695 passengers from the state were on the two trains but 28 passengers were untraced, Education Minister Botcha Satyanarayana said.

The minister said one passenger from the state - Gurumurthy, hailing from Sonthabommali village in Srikakulam district - died in the accident.

However, 22 passengers were injured, one with a severe head injury, and efforts are on to trace 28 passengers who could not be contacted, he said.