Members of the Shiite Houthi movement sit on a pick up truck mounted with a machine gun at a checkpoint in the Yemeni capital Sanaa on January 18, 2015.

The army and Houthi fighters clashed in Yemen’s capital Sanaa on Monday near the Yemeni president’s house, a Reuters witness said.

Gunfire was heard across the city and within close proximity to the president’s residence. No further details were immediately available.

The Houthis, who demand more rights for the country’s Zaydi Shiite Muslim sect, seized Sanaa in September and advanced into central and western parts of the country where Sunnis predominate.

The clashes came after leaders from the southern Yemini provinces gave Houthis late Saturday a 24-hour ultimatum to release the president’s chief of staff, Ahmed Awad bin Mubarak.

The governor of Yemen’s Shabwa province warned Sunday that oil companies will turn off their taps at midnight unless Shiite militiamen in control of the capital free a presidency official.

Mubarak, who was kidnapped on Saturday by the Shiite Huthi militias who control Sanaa, is from the southern province of Shabwa in deeply-tribal Yemen.

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