At least 71 people were killed and 201 wounded in a series of bombings and other attacks across Baghdad on Wednesday, 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.

More than two years of civil war in neighbouring Syria have aggravated deep-rooted sectarian divisions in Iraq, fraying the country's uneasy coalition of Shi'ite Muslim, Sunni Muslim and Kurdish factions.

In Sadr City, an impoverished Shi'ite district in Baghdad's northeast, two car bombs killed seven people. A restaurant owner said he saw an attacker just before one of the explosions.

"A man parked his car in front of the restaurant. He got breakfast and drank his tea. (Then) I heard a huge explosion when I was inside the kitchen," the owner, who requested anonymity, told Reuters.

"When I went outside, I saw his car completely destroyed and he had disappeared. Many people were hurt."

Another car bomb killed seven people and wounded 23 in Jisr Diyala in southeastern Baghdad, police and medics said.

The Interior Ministry described the attacks were "terrorist explosions" but said the number of people killed was only 20, with 213 wounded. The Shi'ite-led Baghdad government has said that media reports exaggerate attacks in Iraq and that security forces have stopped many attempted bombings.

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

ONE THOUSAND DIED IN JULY

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

The renewed violence, 18 months after US troops withdrew from Iraq, has stirred anxiety about a relapse towards the widespread sectarian slaughter of 2006-07.

In other attacks on Wednesday, gunmen killed six members of Al-Sahwa - former Sunni insurgents who rebelled against Al Qaeda - in an ambush on a checkpoint in Latifiya, a suburb 40 km (25 miles) south of Baghdad.

Gunmen also stormed a Shi'ite home in the same area, killing six family members, police and medical sources said.

In Kadhimiya, a neighbourhood in northwestern Baghdad, two roadside bombs and one car bomb killed five people and wounded nearly 30, the sources said.

Four soldiers were killed and five were wounded in Madaen, southeast of Baghdad, by a roadside bomb targeted an Iraqi army patrol, police and medics said.

After years of reduced violence, the intensity of attacks has dramatically risen since the start of 2013. Bombings have often targeted cafes and other places where families gather, as well as the usual military facilities and checkpoints. - Reuters