Britain's spy service, MI5, will begin e-mailing terror alerts to the public on Tuesday, allowing registrants to receive updates should the threat level change.

The current level was set by the government's Joint Terrorism Analysis Centre at "severe" on Aug. 14. The highest level is "critical," meaning an attack is imminent.

Home Office officials say the alerts are part of a push to give the public more information about terrorist threats.

The move also aims to create more transparency at the historically secretive MI5. The government only officially acknowledged the existence of MI5 in 1989, and its leadership remained a secret until 1992.

A second service allows users to subscribe to updates on MI5's website, which might include news about leadership changes or the government's agenda for fighting terrorism, Home Office spokesman Stephen Carter said.

The Home Office is also considering extending the service to mobile phone text messages.

MI5 director general Eliza Manningham-Buller warned in November that Islamic extremists were plotting at least 30 major terrorist attacks in Britain.

The United States and France, which have similar alert systems, do not offer any kind of official e-mail service.

No information overload, it seems

Gordon Correra, the BBC's security correspondent, said people are "not actually getting anymore information than they can get at the moment," but "that information is being made more easily available.

"They [MI5] are kind of feeling their way into engaging with the public more and that's partly that what they used to do was so closed and so secret — the world of espionage and spies," he said.

"But in the world of terrorism, there is a realization they need to be more public."

But he added that one of the difficult questions was what people should do about the information they receive.

"There's not necessarily that much information on the website about how you should act and how you should respond other than being vigilant and calling a hotline if you see anything suspicious."

Tuesday's announcement comes on the heels of a media report that the head of MI5 told a group of senior lawmakers there was no imminent terrorist threat to the country less than 24 hours before the London bombings in July 2005.

Quoting an unnamed source, the Guardian reported that Manningham-Buller told a private meeting of members of parliament for the governing Labour Party on the morning of July 6 there was "no imminent threat to London or the country."

The next day, four British Muslim suicide bombers attacked London's transit system during rush hour, killing themselves and 52 commuters.

with files by the Associated Press