Iraq officials say bombings have killed at least 30 people and wounded at least 65 others.

Authorities say back-to-back explosions rocked the city of Hillah, while another bomb blast erupted in the Shi'ite Muslim holy city of Karbala. Thursday's bombings come just two days after car bombs targeted a Shi'ite procession in Baghdad, killing 12 people.

Both cities are part of Iraq's Shi'ite core located in the country's south. Shi'ites participating in religious events are often targeted by Sunni Muslim extremists.

Shi'ite Muslims marked Ashura in Karbala on Saturday, where hundreds of black-clad Shi'ites gathered near the shrine of Imam Hussein.

Ashura falls on the 10th day of the Muslim holy month of Muharram. The date of Ashura may vary from country to country.