An anonymous letter threatening that the Cauvery Bridge will be blown off was received by the Srirangam railway station master on Friday.
The threat letter written in Tamil and received in the afternoon claimed that the bridge would be blown off using a powerful explosive device with naxal help before March 3.
It went on to further claim that a shop owner at Puthur should give Rs. 7 lakh. If not, the bridge would be blasted using a remote device any time and this would be done with help from the president of the Tiruchi District Photo Association, railway sources said.
The sources said the anonymous letter bore the same name and address of a photo shop at Raghavendrapuram Arch in Srirangam that was mentioned in a similar letter sent to the Kallakudi Palanganatham station master on Tuesday threatening that the Marudhaiyar bridge would be blown off before March 3.
Railway Police are conducting probe into the threat letter.
