Maharashtra's Anti-Terrorist Squad (ATS) has contacted its counterparts in West Bengal and Uttar Pradesh seeking help in tracing an Indian Mujahideen (IM) operative who went underground post the triple bombings, an official said in Mumbai on Saturday.
The operative, reportedly identified as Abdullah, is believed to have recruited several youths into the IM -- a home-grown Islamist terrorist group -- since early this year and was in touch with some people in Karachi, the official from the state police, requesting anonymity, said.
The security agencies have been examining the role of all known and unknown terror groups or their sleeper cells around the country and the operative's sudden disappearance from the security agencies radar is being viewed with suspicion.
The authorities have sought details of passenger reservation charts of trains on the Kolkata-Mumbai and Kanpur-Mumbai routes in the past few weeks.
Some trains operating on this sector terminate at Lokmanya Tilak Terminus and at the Chhatrapati Shivaji Terminus here. The investigators hope to get some clues on the operatives who may have travelled to and from these cities.
On Friday, the National Investigation Agency (NIA) carried out an operation in Ranchi as police were also working around a theory that the Mumbai blasts may not have been carried out by locals.
Around a dozen special teams, comprising officials from different security agencies, have been set up to probe the triple blasts from all possible angles in an effort to crack the case.
The three blasts that rocked central-to-south Mumbai Wednesday evening -- Dadar, Zaveri Bazar and Opera House -- has killed 19 people and injured 129 till date. It was the first terrorist attack in the financial hub of the country after 26/11.