Yemen’s President Abd-Rabbu Mansour Hadi has called for calm after gunfire and explosions on Monday in the capital Sanaa, including near his presidential palace.

The clashes between troops and Shi’ite fighters follow their abduction on Saturday of
Hadi’s chief of staff, Ahmed Awad bin Mubarak. He was seized in efforts by the rebels, known as Houthis, to derail a new constitution.

Claiming they are campaigning against corruption, the Houthis seized Sanaa in September apart from the palace which remains under the control of the presidential guard. They have since advanced into other areas where Sunnis predominate.

Despite a deal calling for a new unity government followed by the withdrawal of Houthi rebels from the capital, the fighters have remained in place in a power struggle that threatens further chaos in Yemen, raising fears al Qaeda could benefit.