Nashik: Security around several important establishments in Nashik, including the Devlali railway station and Currency Note Press, has been tightened after a letter was received by police with a threat to blow them up, a senior official said Tuesday. The Devlali railway station was throughly checked by the Bomb Detection and Disposal Squad on Sunday, the official said. Teams from various police stations as well the Anti-Terrorism Squad are doing rounds of the establishments named in the letter in order to prevent any untoward incident, he added. The Special Branch has begun investigation into the antecedents of the letter, the official said. The unsigned letter, written on an India Post inland letter in coarse Hindi, was received at the Nashik police commissionerate on February 13, city police commissioner Ravinder Singal said Tuesday. (PTI)