A spate of car bombs in mostly-Shia neighbourhoods of the Iraqi capital has killed at least 50 people and wounded almost 80, security and medical officials said.

The bombings struck across Baghdad and left dozens of others wounded on Tuesday, in the latest in a trend of increased attacks in the evening as Iraqis visit cafes and other public areas.

No one has claimed responsibility for the attacks.

I saw a fireball and a huge could of smoke. We couldn't approach immediately, fearing a second bomb. But we could hear the screams of people asking for help.

Ali Jameel, policeman. 

Also, gunmen shot two people dead in Baghdad's southern Dora neighbourhood and four bodies with gunshot wounds to the back were found in different locations around the Iraqi capital, the officials said.

Tuesday's deadliest single blast took place in Baghdad's northern Talbiya neighbourhood, where a car bomb in a busy street killed nine people.

In the Hussainiya district on the northern outskirts of the capital, two car bombs exploded in quick succession, killing ten.

"I saw a fireball and a huge cloud of smoke. We couldn't approach immediately fearing a second bomb, but we could hear the screams of people asking for help," said Ali Jameel, a policeman in a patrol stationed in Hussainiya.

"A minute later a second blast happened nearby. Bodies were lying on the ground and some of the wounded were crawling to distance themselves from the blaze, leaving a trail of blood behind them". 

Violence in Iraq has intensified since April to levels not seen since 2008.

More than 4,000 people have been killed over the past five months alone, including more than 800 in August, according to figures provided by UN officials based in Iraq.

The bloodshed, 18 months after the withdrawal of US troops, has stirred concerns about a return to the sectarian slaughter of 2006-07, when the monthly death toll sometimes topped 3,000.

Earlier on Tuesday, gunmen stormed the house of a Sunni, pro-government armed group member in southern Baghdad and beheaded him, along with his wife and three children, police and medics said.

Separately, four unidentified bodies were found in different places in Baghdad. All of the victims had been handcuffed, blindfolded and killed.

Source: Al Jazeera and agencies