The Ilaam neighbourhood in southern Baghdad was the site of an attack on a police patrol on Wednesday [Reuters]

At least 20 people have been killed and up to 83 others wounded in a series of attacks in the Iraqi capital, according to the country's interior ministry.

In one of Wednesday's attacks, a suicide bomber reportedly drove a car filled with explosives into a police station in Baghdad's central Alwiya neighbourhood, killing at least six people including four policemen.

"The scene was horrific,'' Salim Ghadban, who told the Associated Press news agency he was having breakfast when he heard a loud explosion.

"We saw terrified people, some injured, running in our direction, and we rushed to the attacked police station to see burned bodies and charred cars. We helped cover the burnt bodies until the ambulances arrived.''

A second bomber blew up his car outside a police building in the northwestern Hurriya district, killing at least five people, the Reuters news agency says.

A third attack targeted a police patrol in the southern Ilaam district, killing at least three, police say.

Another blast struck the convoy of a federal police colonel in the north of the city, killing one and injuring 12 people.

Qassim al-Moussawi, Baghdad's military spokesman, blamed al-Qaeda in Iraq for the attacks and said they were an attempt to show people that the group was still active.

"Every three months or so, al-Qaeda mobilises all its resources to launch such attacks in one day to say that [it] is still able to attack and threaten security posts," he said.

The attack in Hurriya was especially unusual because the neighbourhood is almost entirely
surrounded by blast walls, and access is tightly restricted through just four entrances staffed by the Iraqi army.

The apparently co-ordinated attacks were the worst to hit Baghdad since August 28, when a suicide attack blamed on al-Qaeda at the city's biggest Sunni mosque killed 28 people.