The suppressed version of the Sterling (L34A1/Mk.5) was developed for covert operations. This version uses a ported barrel surrounded by a cylinder with expansion chambers. The Australian and New Zealand SAS regiments used the suppressed version of the Sterling during the Vietnam War. It is notable for having been used by both Argentinian and British Special Forces during the Falklands War. A Sterling was used by Libyan agents to kill WPC Yvonne Fletcher outside the Libyan Embassy in London, which sparked the 1984 siege of the building.