Security minister warns of big terrorist plot

LONDON (Reuters) - Security minister Alan West warned on Tuesday that the threat of another major terrorist attack was "huge" and a "great plot" was building.

Speaking in parliament, West, a junior minister at the Home Office, said steps the government had taken over the past 15 months had made Britain safer -- but not safe.

West said one large, complex plot had been unravelled, damaging al Qaeda and causing a slight dip in militant activity.

"They are now building up again. There is another great plot building up again and we are monitoring this," West said.

Security services say they have foiled numerous bomb plots since the September 11, 2001 attacks on the United States and are monitoring thousands of individuals who pose a risk.

"We have always been clear, as has the director general of the security service, that there are many plots, individuals and groups under investigation," a Home Office spokeswoman said when asked to comment on West's remarks.

Britain has been targeted a number of times by people angry about their country's perceived persecution of Palestinian Muslims and those in Afghanistan and Iraq.

Four Islamist suicide bombers killed 52 people on London's transport system and injured hundreds on July 7, 2005. A similar plot two weeks later failed when homemade bombs failed to explode.

Two doctors went on trial this month accused of trying to murder people "wholesale" with car bombs in London and Glasgow last year. Three Britons were found guilty last month of a plot involving homemade liquid bombs in 2006.