Three suspected IS sympathisers, who were arrested recently, were planning to carry out terror attacks on temples and churches in and around the city, police said on Wednesday.
According to the FIR registered against the trio -- Shahjahan, Mohammed Hussain and Sheikh Safiullah -- they had conspired to carry out suicide attacks at temples, churches and places where people gathered in large numbers.
Based on inputs, the police kept the three under watch and claimed to have found them watching video clippings of the Islamic State (IS).
They were arrested on Saturday under the Unlawful Activities (Prevention) Act (UAPA).
The arrests came days after the National Investigation Agency (NIA) raided seven locations in the city and arrested Mohammed Azarudeen, the alleged mastermind of the IS Tamil Nadu module, who was a Facebook friend of Zahran Hashim, the mastermind of the Easter Sunday suicide bombings in Sri Lanka.