BAGHDAD — A series of car bombings and other attacks across Baghdad on Wednesday, Aug. 28, killed 86 people and wounded 263, police and medical sources said, extending the worst wave of sectarian bloodshed in Iraq for at least five years.

It was not immediately clear who carried out the attacks, which appeared coordinated, but Sunni Muslim insurgents, including the al-Qaeda-affiliated Islamic State of Iraq, have significantly stepped up bombings this year.

People gather at the site of a car bomb attack in Baghdad’s al-Shaab district August 28, 2013. REUTERS/Saad Shalash

More than two years of civil war in neighboring Syria have aggravated deep-rooted sectarian divisions in Iraq, fraying the country’s uneasy coalition of Shi’a, Sunnis and Kurdish factions.

In Sadr City, an impoverished Shi’a district in Baghdad’s northeast, two car bombs killed seven people.

Car bombs hit south, north and western Baghdad in a cluster of attacks early in the day and late in the evening, which targeted both Shi’a and Sunni areas of the capital.

The Interior Ministry described the attacks as “terrorist explosions,” but said the number of people killed was only 20, with 213 wounded. The government has said that media reports exaggerate attacks in Iraq and that security forces have stopped many attempted bombings.

However, Wednesday’s violence was the worst since August 10, when nearly 80 people were killed during a religious holiday.

More than 1,000 Iraqis were killed in July, the highest monthly death toll since 2008, according to the United Nations.