Giving details of the arrest, ATS chief Atulchandra Kulkarni said the accused had stored a huge cache of explosive materials, adding that they would be questioned about all the cases in which the involvement of right-wing extremists was suspected.
"We will question them regarding all the detected and undetected cases, including the (rationalists) Narendra Dabholkar, Govind Pansare and (journalist) Gauri Lankesh (murder) cases," he said.
The ATS zeroed in on the accused on the basis of information that some persons were planning to carry out acts of sabotage at many places in the state, Kulkarni said.
Raut allegedly ran the "Hindu Govansh Raksha Samiti", a little-known pro-cow protection outfit, in Nallasopara, a police officer had said earlier.
While Raut's purported account on a social media platform mentioned that he was associated with right-wing group Sanatan Sanstha, the outfit today denied that he was its member.
The raid at Raut's house at Bhandar Aali in Nallasopara West and at a nearby shop owned by him led to the seizure of 20 crude bombs, two gelatin sticks, four electronic and 22 non-electronic detonators, 150 gm of explosive powder, two bottles labelled as "poison", batteries, soldering equipment and a bomb circuit drawing, according to the ATS.
The seized materials were sent to the Forensic Science Laboratory.
According to the police, Raut is an estate agent, Kalaskar works in a private firm, while Gondhalekar runs his own business.
They were under police surveillance for the last two weeks, another ATS official said, adding that all three seemed to be "trained for sabotage activities".
The ATS sleuths were probing if they had a plan to carry out any terrorist act ahead of Bakri Eid this month, he said.
As they were in possession of explosive materials, it seemed that they were not mere "foot soldiers" of the "extremist gang" they were members of, the official added.
The ATS has arrested the three under IPC section 120B (criminal conspiracy), provisions of the Explosives Act as well as Unlawful Activities (Prevention) Act (UAPA) sections 16 (punishment for terrorist act), 18 (conspiracy for terrorist act) and 20 (being a member of terrorist gang).
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)