After the Hirakhand Express derailed in Andhra Pradesh's Vizianagaram district claiming the lives of 41 people and leaving more than 50 injured in the mishap, a team from the National Investigation Agency (NIA) and Crime Investigation Department (CID) visited the site on Monday to investigate the possibility of sabotage.
On Monday both the teams questioned several people including the train driver and guard.
Forensic experts from NIA collected the evidence from the spot which will be analysed at Forensic State Laboratories (FSLs) in Hyderabad and Visakhapatnam.
The NIA team which visited the spot has reportedly ruled out the possibility of an Improvised Explosive Device (IED) being used, as the cause of the mishap.
Quoting NIA sources, a report in the Times of India adds that the possibility of Maoists could only be ruled out after the forensic report.
Meanwhile, the AP CID team which visited the spot has also remained mum.
Officials have not ruled out the involvement of Maoists as the Andhra-Odisha border area is considered a Maoist stronghold.
â€śWe are not ruling out any possibility till the forensic report is out,â€ť AP CID chief Ch Dwaraka Tirumala Rao told the media.
At the FSL, experts are expected to analyse pieces of the railway track, to see if it was deliberately cut, or broke following the derailment.
Meanwhile, the gatekeeper at the Kuneru railway station, D Apparao said that he saw a spark under the locomotive, when it was entering the station.
â€śImmediately, I informed the station master. But, before any instruction reached me, I heard a big sound. It was nothing but the derailed coaches hitting one another,â€ť he told Deccan Chronicle.
The accident case registered by the Vizianagaram Government Railway Police (GRP) has been transferred to the AP CID by the Andhra Pradesh government.
The AP CID chief mentioned that five probe teams have been formed to carry out the investigation. While one of the team will investigate the explosive angle, the second will check if any chemicals were involved. The third team will deal with the technical angle, while the fourth and fifth teams will examine post mortem reports and question injured people.