Following the bombings, a small forward element of the CRW was permanently deployed to the capital to provide immediate assistance to the Metropolitan Police Service in the event of a terrorist incident. This unit is supported by its own attached Ammunition technical officer trained in high-risk search and making safe car bombs and improvised explosive devices, along with a technical intelligence cell capable of sophisticated interception of all forms of communication. In particular, after 21 July bombings, several SAS elements trained in explosive methods of entry were dispatched to support the Metropolitan Police firearms unit, and were used to explosively breach two flats where would-be suicide bombers had taken refuge, the police fired CS gas into both premises and negotiated the surrender of all suspects.