A car bomb exploded in a busy market in northeastern Iraq on Thursday, killing at least 25 people and wounding more than 30, the town's mayor and medical sources said.

Iraq is currently suffering its worst wave of violence in at least five years, with insurgents targeting mainly Shi'ite Muslim civilians in attacks on public places such as shopping areas and cafes.

Thursday's attack took place in Sadiya, in the Diyala province, 40 miles northeast of Baghdad.

"I was sitting in my store when I heard a huge explosion. I could not recognize anything because dust engulfed the place. Shattered glass was everywhere," grocery store owner Suhair Gadhban told Reuters by telephone, adding that he had been wounded in the leg.

Suhair said he had seen dozens of people lying near the scene of the explosion as he was being taken for medical aid.

"Some of them had been killed and others were seriously wounded and were screaming for help," he said.

Hundreds of Iraqis have been killed each month in 2013 and the frequency and severity of bomb attacks has raised fears that Iraq could descend once more into the kind of sectarian bloodshed of 2006-2007, when tens of thousands died.

Nearly two years since U.S. troops withdrew from Iraq, security forces are struggling to combat violence across the country. Insurgents, some linked to al-Qaeda, have also benefited from the civil war in neighboring Syria.

Reuters