Shimla, July 10 -- Anonymous e-mails threatening to blow up six district courts at Chakkar and Rampur in Shimla, Nahan in Sirmaur, Kinnaur, Kullu and Chamba on Wednesday triggered panic and led to the evacuation of the six premises, affecting legal proceedings. As per the police apart from the district courts, an e-mail was also received threatening to blow up the office of headmaster, Sanawar School, Solan. The e-mails alleged the presence of RDX-based improvised explosive devices (IEDs) at these locations. Acting promptly, police evacuated the six court complexes and the school and thorough searches were launched. Bomb disposal squads and sniffer dogs were requisitioned, but after no explosive was found, work resumed. Police in a statement said the contents of all e-mails were similar and were believed to have originated from a single source. A senior police officer said the e-mails were sent via virtual private network (VPN) to mask the sender's identity: "All e-mails are treated seriously and appropriate action is taken, including sanitisation of locations." Following registration of FIRs, an investigation has been initiated to trace the origin of the e-mails, reportedly sent in the name of former students of Anna University, police added. This is the eighth such threat incident reported in Himachal Pradesh since January when a threat to blow up government offices was received. All seven bomb threat e-mails had turned out to be hoax....