Baghdad ( CNN ) -- Three bombings targeted Shiite pilgrims Monday in and around Karbala , Iraq , killing at least 33 people , officials said . A suicide car bombing in the small town of Twareej , just outside Karbala , killed at least 20 people and wounded 35 others , Interior Ministry officials said . Earlier , at least 13 people died when a car bomb exploded in a Karbala bus station crowded with Shiite pilgrims , who had traveled to the city for a religious observance , according to the Interior Ministry . Another 45 people were wounded in the attack , which came near the peak of the Arbaeen , a religious observance that is one of the holiest days in the Shiite religious calendar . An hour after the bus station bombing , a roadside bomb targeting Shiite pilgrims exploded in Karbala , wounding six people . Karbala is located about 100 kilometers ( 60 miles ) south of Baghdad . The dead and wounded included women and children , and were among the hundreds of thousands of Shiite pilgrims who have gathered in Karbala for the observance . The Arbaeen is the culmination of 40 days of mourning for Imam Hussein , a grandson of Mohammed who died in a 7th century battle in Karbala . The latest explosions come four days after multiple bombings that left 50 people dead and 150 wounded , most of them Shiite pilgrims . Also Monday morning , the governor of Iraq 's Salaheddin province escaped unharmed after his convoy hit a roadside bomb in central Tikrit , police said . Five of Gov . Ahmed Abdullah 's guards were wounded in the attack , Tikrit police said . Tikrit is about 160 kilometers ( 100 miles ) north of Baghdad . CNN 's Mohammed Tawfeeq contributed to this report .
NEW : At least 33 killed in two bombings . The first targeted Shiite pilgrims in Karbala for a religious observance . Police say 5 of the Gov . Ahmed Ali 's men are wounded in another bombing .