Security has been tightened across Haryana and Himachal Pradesh after an official of the Ambala Cantonment railway station Tuesday received a threat letter, officials said.
The letter threatened to blow up railway stations and religious places in the state "to avenge the atrocities against Muslims by Hindus", Station House Officer (GRP) Ram Bachahan said.
"The station director at the Ambala Cantonment railway station on Tuesday received a letter threatening to blow up a few railway stations of Haryana and Himachal Pradesh including Ambala Canttand various religious places," Bachahan said.
The station's director B S Gill found the letter on his table, he said, adding that there was no stamp of a post office on the letter cover.
The station director had received a similar threat a few months ago, he said further.
A security alert has been issued at most of the railway stations and other vulnerable places in in Haryana and Himachal Pradesh, the SHO said.