A suicide car bomb explosion ripped through a police checkpoint in Baghdad Tuesday, killing 23 people and wounding more than 40

A suicide car bomb explosion ripped through a police checkpoint in Baghdad Tuesday, killing 23 people and wounding more than 40, police and medical sources said.

The suicide bomber detonated an explosives-laden vehicle at an entrance to the northwestern neighborhood of Kadhimiyah, a police colonel and an interior ministry official said.

At least five of those killed were policemen, as were eight of those wounded, said police and medical sources, who both gave figures higher than 40 for the number of wounded.

The predominantly Shiite neighborhood of from the mainly Sunni district of Adhamiyah and is frequently targeted when sectarian tension in the country is high.

Kadhimiyah, which lies across the Tigris river and is home to one of the holiest Shiite shrines, is named after Musa Kadhim, the seventh of 12 revered imams in Islam.

Another three people were killed when a suicide car bomb went off in a market area in the town of Nahrawan, around 20 kilometers (12 miles) southeast of the capital, a senior police officer told Agence France Presse. At least eight were wounded.

The escalation of violence came after the Islamic State in Iraq and the Levant terrorist group declared a "caliphate" straddling Iraq and Syria.