4 Killed in Iraq Blasts

Iraqi officials say bomb attacks in a Baghdad district and a mainly Shi'ite area north of Baghdad have killed four people and wounded 11. 

Farther south, officials say a suicide bomber detonated an explosive belt between two Shi'ite shrines in the holy city of Karbala -- wounding several other people.

The bomber set off the explosives near the shrines of Imam Hussein and Imam Abbas. 

There was no immediate claim of responsibility, but Sunni Muslim militants in Iraq frequently attack the country's majority Shi'tes to inflame sectarian tensions and undermine the Shi'ite-led government.