A threat to kidnap and murder a serving West Midlands police officer led to a security alert being issued to staff, the BBC understands. The force has confirmed counter-terror officers are investigating an ‘anonymous but credible’ tip-off. Staff were first told on Monday night after the force received the call. Assistant Chief Constable Garry Forsyth said the force was taking the threat ‘extremely seriously’, but there was no increased risk to the public. Officers have been urged to take extra precautions, including not wearing uniform during journeys to and from work. West Midlands Police said it had ‘implemented additional security measures’ after obtaining the information but the force declined to confirm the exact nature of the threat. A spokeswoman said counter-terror officers were continuing to assess the anonymous information the force had received. Officers were held on duty while they were given the security reminder as they started their shifts.