Saudi authorities, on alert after suicide blasts in Riyadh last week, have arrested four men on suspicion of belonging to the al Qaeda network, a diplomat said Thursday. “They arrested four Tuesday on suspicion of connections with al Qaeda,” the Western diplomat in Riyadh said, adding that Saudi police were aggressively searching the vast desert kingdom for operatives of the Islamic militant group. A triple suicide bomb attack on foreign residential compounds last week killed 34 people, including eight Americans, in attacks blamed on al Qaeda, which is led by Saudi-born Osama bin Laden. Stung by U.S. accusations of not doing enough to prevent the Riyadh bombings, Saudi Arabia has said it was stepping up security measures in the country, the birthplace of Islam. Full Story