Masked Italian anti-terrorism police officers, right, arrest an unidentified man believed to be a member of the Ansar al-Islam extremist group, in Florence, Italy, Sunday, May 9, 2004. Anti-terrorism police squads arrested the Algerian imam of a Florence mosque and four Tunisians Sunday in a crackdown on the Ansar al-Islam extremist group, agencies reported Sunday. (AP Photo/Francesco Bellini)