London Mayor Boris Johnson says he has accepted the resignation of the top counterterrorism officer in the Metropolitan Police, according to AP. The mayor says Bob Quick, who was the senior police counter-terrorism officer in Britain, stepped down Thursday after a security blunder forced police to move up the timing of an anti-terror operation in northern England. On Wednesday, Quick was photographed clutching confidential documents that could clearly be seen as he arrived in Downing Street for a meeting with Prime Minister Gordon Brown. The documents showed details of a major anti-terror operation in northern England. In subsequent anti-terror raids, police arrested a dozen men.