At least 12 Iraqi worshippers were killed and up to 25 others injured on Friday in a suicide bombing inside a Sunni mosque in a town near the volatile city of Mosul, the capital of Nineveh province, an Interior ministry source said.

The incident occurred when a bomber blew up his explosive belt among worshippers inside the al-Taqua mosque in the Hasan Koiee neighborhood in the town of Tal Afar, some 70 km west of Mosul during Friday noon prayers and caused the casualties, the source told Xinhua on condition of anonymity.

Iraqi security forces immediately cordoned off the area to secure the scene, while ambulances rushed to take the victims to nearby hospitals, it added.

Mosul, some 400 km north of Baghdad, is said to be one of the last strongholds of al-Qaida fighters in the war-torn country.

The province has been the scene of a major security crackdown by U.S. troops and Iraqi security forces, which was aimed at uprooting al-Qaida militants and other anti-U.S. insurgent groups.