President Bush is set to arrive in Britain tomorrow on the first state visit by a U.S. President since President Woodrow Wilson in 1918.

Five thousand officers and hundreds of security agents will protect the President during the series of protests planned to mark his stay, including a mass national rally on Thursday. Extra police are at ports and airports, and have been checking people arriving on Eurostar trains from France. Bush will also be protected by hundreds of armed guards from the US.

Separately, British security services were placed on their second highest state of alert following information that al Qaida supporters in North Africa could be planning an attack. The alert is said to be unrelated to the President’s visit but will further tighten security on what was already described as an “unprecedented” policing operation.