Baghdad, May 27 (IANS) At least 19 people were killed and 34 others wounded in a suicide bomb attack at a Shia mosque in Iraq's capital Baghdad Tuesday, a police source said. The attack occurred at **on when a suicide bomber blew up his explosives-vest among a crowd of Shia worshippers at the mosque at Shorjah commercial area in downtown Baghdad, the source told Xinhua on condition of a**nymity. Iraq is witnessing some of its worst violence in recent years.