Police in northern Iraq say a car bomb has exploded outside a Christian church in the ethnically-divided city of Kirkuk, wounding at least 23 people.

Authorities said the blast Tuesday damaged the church as well as homes in the area.

As many as 1.2 million Christians lived in Iraq before the 2003 invasion to oust leader Saddam Hussein. However, many have since fled abroad in the wake of stepped-up violence by al-Qaida-linked Muslim insurgents.

In October 2010, al-Qaida militants carried out a deadly siege of a Christian church in Baghdad that left 46 worshippers dead.

Kirkuk is an oil-rich region that has long experienced tensions among its Arab, Kurdish and Turkmen communities. Arab residents oppose demands by the Kurds to annex Kirkuk to northern Iraq's autonomous Kurdish region.