Four years after the 7 July 2005 terrorist attacks on the London Tube, a review of the government's counter-terrorism policy says the rail service remains "extremely vulnerable" to similar attacks, guardian.co.uk reports.
The review, compiled by the Commons Home Affairs Select Committee, stated that the Tube will always be a "high-profile and iconic target" for terrorists.
The report also adds that the rail service could never adopt an airport-style security system because of the huge volume of daily passenger traffic.
The review has revealed these findings even as a number of counter-terrorism exercises have been staged post the 2005 attacks to better prepare staff. Since then, a new system, Airwave, has also been introduced for underground communications between the emergency services and London Underground staff.