BAGHDAD (AFP) - The Islamic State in Iraq and Syria (ISIS) extremist group on Thursday claimed a suicide bombing at a police headquarters in west Baghdad, saying it was carried out by a Dutch national.

In an online statement, ISIS said that "Abu Abdullah al-Hollandi" carried out the attack using an explosives-rigged belt.

Security and medical officials said the Wednesday suicide bombing was preceded by a nearby car bomb and that the two attacks killed a total of 11 people and wounded 23.

But the ISIS statement said that information was not correct, and that there was only the suicide bombing.

ISIS spearheaded a militant offensive in June that has overrun large parts of the country, and security forces and pro-government fighters are battling to push them back.

They are now supported by US-led air strikes targeting ISIS in both Iraq and neighbouring Syria, while Washington and other governments have also pledged trainers to aid Iraqi forces.

Baghdad is hit by near-daily bombings and shootings that kill hundreds of people each month.

Despite being deployed at checkpoints and other positions across the city, security forces are consistently unable to prevent attacks.