The National Investigation Agency (NIA) on Thursday searched five locations in Tamil Nadu's Coimbatore district.
The raids were in connection with persons suspected to have connections with terror organisations. The action follows a high alert issued in the state last week following intelligence inputs about infiltration by six Lashkar men from Pakistan via the Sri Lanka route.
Five teams of the NIA were carrying out the raids. So far several laptops and pen drives have been seized, an officer said.
The intelligence agencies have warned of planned terror attacks by the infiltrators at places of worship and other vital installations.