A car bomb exploded Saturday near a mosque in the Old City of the rebel-held Yemeni capital Sanaa, causing casualties, witnesses and security sources said.

The explosion went off outside the Kobbat al-Mehdi mosque where Shiite Muslims are known to pray, the sources said, without being able to specify how many people were killed or wounded.

Iran-backed Shiite rebels known as Huthis overran Sanaa in September last year and have since expanded their control to other parts of Yemen, forcing President Abedrabbo Mansour Hadi and his government to flee to Saudi Arabia.