Gunfire was also heard across the city early on Monday as Houthis closed off all the streets leading to the palace, witnesses told Al Jazeera.

The situation has been very tense for the past two days following the Shiite group's detention of the president's chief of staff.

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

A deal signed in September between political parties and the Houthis called for the formation of a new unity government followed by the withdrawal of Houthi fighters from the capital.