Syed Ahmed Ali, a native of Tripura, was arrested at Ambur in a swift operation in coordination with Uttar Pradesh Police and the Intelligence Bureau, which alerted about his presence in the state, police said.
Ali had allegedly made terror threats to Taj Mahal in Agra, a dargah besides an institution in Lucknow. He had arrived here two days ago and stayed in a Madrasa in Ambur.
"Ali claims that he came to Tamil Nadu to take medical treatment in Christian Medical College here. He made a threat call to the CMC hospital and he claims that he did that as treatment was delayed," a senior police official told PTI.
Eight SIM cards were found in his possession and one of them was used to make the threat call to the CMC hospital.
Following his arrest, a local court remanded him to judicial custody and he had been lodged in the Vellore Central Prison, the official added.
Intelligence Bureau officials alerted Tamil Nadu police about the presence of Ali in Ambur in a Madrasa.
"We immediately began our probe and with the help of local people we identified Ali...Now Uttar Pradesh police are on their way to take this man into their custody through court," the official added.