The Tamil Nadu Police's special team probing the twin blast on Bangalore-Guwahati Express suspects that bombs could have been kept in the train at Bangalore railway station.
After chief minister J Jayalithaa ordered a CB-CID probe into the blasts that killed a 24-year-old IT employee and left 14 injured, a team reached Bangalore on Friday--from where the train had started its journey for Guwahati late on Wednesday night. The CB-CID also released CCTV footage of a possible suspect who was seen running on the platform after the arrival of the train at Chennai Central railway station.
"The CCTV footage of cameras installed at various places is being scrutinised… The movement of a person found in the clippings was found to be unusual and it needs verification," Mahesh Kumar Agarwal, IG, CB-CID said.
"A case in central railway police station crime no 273/2014 under sections 307, 302, 326, IPC 3, 4, 5 of Explosive Substances Act and 151 of Railway Act was registered and preliminary investigation was taken up by railway police. On the orders of the CM, investigation in the case had been transferred to Crime, CID," he added.
"Collected material is being subjected to forensic analysis to identify the nature of the explosive material used and the type of device… Similarities have been found between the bombs used here and the bombs found in Patna."
The team of the Crime Branch-Criminal Investigation Department (CB-CID), a special investigating unit of Tamil Nadu, is working closely with the Karnataka Police.
Officials are conducting a background check on eight passengers who did not board the train despite having tickets for the journey.
Sleuths are also trying to verify some eye witnesses' claim that they saw four men placing a bag in the train.
An official said the information collated so far suggested bombs fitted with timer device could have been planted at Bangalore station.
"We are studying the footage to see if the accused actually travelled in the train," the official said.
No arrest has been made in the case till the filing of this report. Sources said the Tamil Nadu Police had picked up two persons for questioning, but let them off on Friday.
Meanwhile, reacting to Tamil Nadu's decision not to allow an investigation by the National Investigative Agency (NIA), home minister Shushilkumar Shinde said the the central agency cannot act directly without the state's cooperation.
He, however, added an NIA team would be sent to Chennai for data collection.
Strongly opposed to any interference from central agencies on law and order, Jayalalithaa refused to take any help from the Union government, even as the explosions on Thursday sent a shock wave across the nation.
Anoop Jaiswal, Tamil Nadu director general of police (in charge of elections), however, said there was no Centre-state confrontation on the issue.
In another development, a six-member National Security Guard (NSG) team had arrived in Chennai last night to help the state police. The team inspected the affected bogies on Friday morning.
The Commission of Railway Safety too began its own investigations.
(With inputs from Gaurav Bisht from Shimla and agencies)