Simultaneous early morning attacks on mostly Shi'ite targets across Iraq killed at least 60 people and wounded dozens on Thursday, February 23 in one of the bloodiest days of violence since U.S. troops pulled out in mid-December, News 24 reported.

The attacks that appeared to pitch al-Qaeda-linked Sunni Muslim insurgents against Shi'ites raised fears of a return to the widespread sectarian carnage that tore Iraq apart and cost thousands of lives in 2006 and 2007.

The violence breaks weeks of relative calm as Shi'ite Prime Minister Nuri al-Maliki and Sunni leaders have sought to resolve a political crisis that followed the U.S. withdrawal.

At least 32 people were killed in blasts in Baghdad where 10 explosions tore through mainly Shi'ite neighbourhoods during rush hour and other attacks targeted police patrols, commuters and crowds gathered in shopping areas.

More than a dozen blasts and attacks hit other cities across Iraq from Mosul in the north to Hilla, south of Baghdad, many of them targeting police.

The violence was aimed at Shi'ite neighbourhoods and security forces, a frequent target of Sunni insurgents. Iraqi officials had predicted such groups would try to stir sectarian tensions with attacks after American forces went home.