The head of MI5, Jonathan Evans, briefed the cabinet on the terrorism threat in the run up to the London 2012 Games.
Evans warned that terrorists could target Olympic venues outside Londo, in his first ever address of the entire Prime Minister senior team.
Olympic and Paralympic rowing events will happen at Eton Dorney near Windsor Castle, 25 miles from London, road cycling will be held in Kent, and sailing events will take place in Weymouth.
There are also stadiums in Newcastle, Coventry, Cardiff and Manchester.
Downing Street officials called the update “routine” and not sparked by any new intelligence or change in the terrorism threat level, which is currently “substantial”.
Prime Minister David Cameron’s spokesman called it “an overall assessment of the current terrorist threat to the UK”.
Another Downing Street spokesman said: “It was a broad discussion about terrorism and an assessment of the current threat and a run-through of the various issues that the Government is dealing with on the legislative side, such as the fact that we have replaced control orders with TPIMS (Terrorism Prevention and Investigation Measures) and the various measures that are being considered in the context of the security and justice Bill.”