Bombs killed at least 11 civilians in central Baghdad on Sunday when they exploded at two restaurants in the Iraqi capital, police and medical sources said.

Police said the deadliest explosion took place near Tahrir Square when a bomb placed in a plastic bag exploded near a popular restaurant, killing seven people and wounding 11 others.

In a separate incident, four people were killed and eight wounded when a bomb went off near a small restaurant in central Baghdad's Sibaa district, police and medics said.

It was not clear why the restaurants were targeted, and no group immediately claimed responsibility for the attacks.

Sunni Islamist insurgents from Islamic State, which controls large swathes of territory in Iraq's north and west, have claimed responsibility for several recent bombings and suicide attacks in the capital.