In yet another bomb threat in the aftermath of sandalwood smuggler Veerappan's killing, a pro-Tamil forum has threatened to blast Doordarshan's relay station at Sikkil near Nagapattinam.

Panic gripped the station on Monday after the receipt of the letter sent under the name of "Tamizhar thanmaana peravai" (Tamils' pride forum) threatening that a bomb would explode in the relay station.

• The Veerappan Saga

Relay station assistant engineer Rani Asirvatham said a police team and a bomb squad led by Nagapattinam assistant superintendent Damor Deepak carried out a thorough check of the station premises, but found no explosives.

Security had been tightened for the station and other state and central government officies in the region as a precautionary measure.

In the letter posted on October 22 in Nagapattinam, the forum said it had decided to plant bombs in the station and asked the employees to take precautions.

The Tamil Liberation Army had last week threatened to plant bombs at several railway stations in the state if the officials who killed Veerappan were not immediately suspended from service.