Umesh Kolhe was killed by two men on a motorcycle, who slit his throat.
Last month's gruesome killing of a chemist in Maharashtra's Amravati for defending a controversial social media post against Prophet Muhammad was "an act of terror", government sources have said, adding that the role of terrorists with foreign links, "self-inspired" by ISIS, is being probed.
The National Investigation Agency (NIA) on Wednesday conducted searches at 13 locations in Maharashtra in connection with the killing of chemist Umesh Kolhe. In its First Information Report (FIR), the agency has called it "an act of terror to terrorise a section of people".
Pamphlets spreading hate messages and knives were found in the searches from the premises of the accused, sources said. Seven people had been arrested by the police before the case was taken over by the central anti-terrorism agency.
"Easter bombings in Sri Lanka were also self-inspired by ISIS, and it seems like this gang was also self-inspired by ISIS," a senior official told NDTV, requesting not to be named.
According to him, the NIA, in its searches, also recovered digital devices including mobile phones, SIM cards, memory cards, digital video recorders, and other incriminating documents and materials.
The NIA is also investigating whether the case is part of a national conspiracy or has roots abroad.
Umesh Kolhe was killed on June 21 by two men on a motorcycle, who slit his throat, allegedly for sending a WhatsApp message in which he had supported former BJP spokesperson Nupur Sharma who made objectionable remarks against Prophet Muhammad.
The incident took place a week before Kanhaiya Lal, a tailor in Rajasthan's Udaipur, was killed similarly at his shop by two men, who posted a video of the murder and said that they were avenging an insult to Islam, for a similar social media post.
The NIA's FIR has listed Mudassir Ahmed, Shahrukh Pathan, Abdul Thoufik, Shoaib Khan, Atib Rashid, Yusuf Khan, Shahim Ahmed and Irfan Khan as accused along with unknown others. All seven accused are in the custody of NIA.