Police in Britain say that a fifth suspect has been arrested in an alleged plot to kill British Prime Minister Gordon Brown.

Greater Manchester Police say the latest suspect is a 29-year-old man arrested Tuesday in Derby in central England. Police are still questioning three men arrested on Aug. 14.

Police also said Wednesday that their search of an address in Derbyshire is expected to continue for several days.

Last week, the British Broadcasting Corp. reported that the first three men arrested were being held in connection with a Web site posting signed “al-Qaida in Britain” that threatened the life of Brown and his predecessor, Tony Blair.