The searches were a continuation of those conducted here and in Kerala in connection with an Islamic State terror module.
After carrying out searches at seven locations in the city on Wednesday, the NIA had detained six people for questioning and arrested prime accused Mohammed Azarudeen, who was a Facebook friend of Sri Lankan Easter Day blasts mastermind Zahra Hashim.
29-year-old Riyas A, also known as Riyas Aboobacker or Abu Dujana, a resident of Palakkad was a follower of Sri Lankan Easter bombing mastermind Zahran Hashim.
The NIA on Thursday filed a chargesheet against six people in connection with the October 2022 Coimbatore car bomb blast, saying the prime accused of the terrorist attack was "inspired by ISIS ideology".
The input was sent through diplomatic channels to the island nation after a through investigation pertaining to the IS case in Coimbatore was carried out by the NIA.
In searches carried out in the city earlier, the NIA had arrested two people -- Mohammed Azarudheen and Shiek Hidayathulla.
The NIA had alerted the island nation that ISIS terrorists were planning to carry out strikes there.
A tribunal of the Delhi high court has confirmed the extension of a five-year ban imposed on Islamic Research Foundation, set up by fugitive Zakir Naik who is accused of inspiring Muslim youths in India and abroad to commit terror acts.
The reports suggested six members of the terror outfit infiltrated into the state by sea from Sri Lanka and moved to different cities, including Coimbatore, according to the police.
'What happened last Sunday is a great tragedy, an insult to humanity'