The National Investigation Agency on Thursday conducted searches across multiple locations in Coimbatore in connection with its ongoing probe into the Islamic State Kerala-Tamil Nadu module.
The searches were carried out at five locations based on warrants issued by a special NIA court, Ernakulam, the agency said in a release.
"During searches today (Thursday) at the houses of five associates of the accused persons, digital devices, including 1 laptop, 5 mobile phones, 4 SIM cards, 1 memory card and 8 CDs/DVDs, and a large number of incriminating documents have been seized," it said.
The seized digital devices will be subjected to forensic examination, it added.
The suspects were being questioned about their association with the arrested persons and their involvement in the conspiracy aimed at furthering the objectives of the IS, the NIA said.
The agency had registered the case in May this year.
It was registered on the basis of information that some individuals were propagating the IS ideology on social media with an intention to recruit vulnerable youth to the proscribed terror group and carry out attacks in south India, especially in Kerala and Tamil Nadu, it said.
According to the NIA, some of the accused and their associates were in touch with Zahran Hashim, the suspected mastermind behind the Sri Lanka Easter blasts, and his accomplices through social media.
In searches carried out in the city earlier, the NIA had arrested two people -- Mohammed Azarudheen and Shiek Hidayathulla.
Earlier, police had said Thursday's raids were conducted at the residences of the suspects in connection with a recent terror alert issued in Tamil Nadu and to ascertain if they had any links with Lashkar-e-Tayiba (LeT) terrorists who had infiltrated into the state last week.
Reports had said six LeT terrorists had infiltrated into Tamil Nadu by sea from Sri Lanka and moved to different cities, including Coimbatore.
Security was subsequently beefed up across the state.
The vigil, however, has been eased gradually since Monday.