Car bombs in Iraq on Sunday killed at least 28 people in Baghdad and wounded dozens more, AP reported .
Most of the blasts happened in predominantly Shia Muslim areas of the city.
The attacks come amid heightened sectarian tensions across Iraq , which had dropped off since the widespread sectarian clashes in 2006 and 2007 subsided.
Three cars exploded in the poor Shia neighborhood of Sadr City, followed by other blasts in al-Amin and an open-air market in Husseiniya, just north of the capital, and in the eastern suburb of Kamaliya.
Protestors from Iraq’s Sunni minority have staged weekly anti-government demonstrations since late December , calling for Prime Minister Nouri al-Maliki - a Shia - to step down.
There are growing concerns that Sunni paramilitaries will stage more attacks ahead of provincial elections planned for April 20, the first national vote since the U.S. withdrew its combat troops more than a year ago.