With joyous ululations, thousands of Iraqis have celebrated for the first time the arrival of the "Holy Fire" brought from Christianity's holiest site in Jerusalem to mark Orthodox Easter.With chanting and prayers, excited crowds gathered Saturday night to greet the flame's arrival at the Syriac Christian Orthodox Mar Matta monastery of Saint Matthew, about 28 kilometres (17 miles) from the war-ravaged city of Mosul in northern Iraq.