ISLAMABAD The British High Commission, Islamabad received a threatening call and was warned to shut down its offices across the country otherwise the offices would be blown up. According to details, an unidentified man while allegedly impersonating himself as member of a militant outfit, telephoned the British High Commission (BHC) and warned the Commission to close down all of its offices otherwise they would be blown up with explosives. This incident surfaced on Thursday night when Security Manager British High Commission, Cap (Retd.) Shakeel-ur-Rehman lodged an application with the Secretariat Police Station stating that the BHC received a threatening call from an unknown caller. On this, police registered an FIR against the unidentified caller under the Section 25/D the Telegraph Act. Police said they have started investigation into the matter.