Authorities were sent into a tizzy after an anonymous letter received by the Magistrate's office in the morning stated that a "human bomb" had infiltrated the court premises.
The cases were immediately adjourned and judges and advocates left the court premises.
Police thoroughly checked the area and also some persons but no explosives were found.
Strict vigil is being maintained in Rameswaram, Madurai and Nagapattinam after an intelligence bureau alert that terrorists had sneaked into Tamil Nadu and were planning to launch attacks in these coastal areas, police said.