Co-ordinated bomb and gun attacks in the heart of the Iraqi capital Baghdad have killed at least 21 people.

The incidents, which also wounded at least 50 others, took place near the Allawi area, not far from the heavily fortified green zone which houses several Western embassies and Iraqi government offices.

Police said two car bombs were detonated – one near the Justice Ministry and the other close to the Interior Ministry's offices.

A suicide bomber then walked into the Justice Ministry building and blew himself up.

The offices were also attacked by a group of gunmen wearing police uniforms.

After a gun battle, lasting about one hour, security forces regained control.

Among the dead were six policemen, 12 civilians and at least three insurgents, police said.

No group has claimed responsibility for the attacks.

The country's security is under growing strain as the sectarian conflict in neighbouring Syria reignites Iraq's own combustible Sunni-Shi'ite mix.