A tense calm has taken hold of Yemen's capital, Sanaa, as Houthi rebels continued to surround the prime minister's residence and the presidential palace, despite reaching a ceasefire after a day of violence.

A heavy presence of Houthi fighters was seen throughout Sanaa on Tuesday, as the rebels fortified their positions in the capital, which they seized in September last year.

Armoured vehicles blocked roads with access to the residence of Prime Minister Khaled Bahah in the city centre, and to the presidential palace in the south of the capital.

Al Jazeera's Omar Al Saleh, reporting from Yemen, said the situation in the capital was "tense but calm".

"A meeting is supposed to take place between all political players; President Abd Rabbu Mansour Hadi, Prime Minister Bahah and representatives of the Houthis, but it remains unclear if these talks have started.

"We're all waiting to hear from this meeting," our correspondent said, adding that the UN Security Council was scheduled to discuss the situation in Yemen in a closed session later on Tuesday.

The truce was accepted during a meeting on Monday between a representative of the Shia Houthis and Yemen's defence and interior ministers.

Although a ceasefire agreement was reached, there still were several clashes near the presidential palace on Monday afternoon.

Houthi demands

The latest violence appears to be linked to the Houthis' rejection of a draft constitution that would divide the country into six federal regions.

Fierce clashes rocked Sanaa on Monday

On Saturday, the Houthis kidnapped one of Hadi's top aides, Ahmed bin Mubarak, to disrupt a meeting on the charter. The US, Saudi Arabia and other backers of the Yemeni leadership have called for his immediate release.

In a statement on Monday, a Houthi spokesman, Mohammed Abdel-Salam, said the charter should only state that Yemen will be a federal state without specifying the number of regions.

"Let the wise men of this people agree later on the regions and how to form them and their details," he said.

On Sunday, Hadi issued a statement demanding the army defend Sanaa, state media reported, though it was not clear whether Hadi, who has made similar calls in the past, was ordering the security services to take back control of the city.

Hadi and the Houthis accuse each other of failing to implement a UN-brokered peace deal calling for Hadi to form a new national unity government and reform government agencies and for the Houthis to withdraw their fighters from cities.

The Houthis have also demanded integration of their militiamen into Yemen's security forces, something Hadi strongly opposes.

The prolonged power struggle has undermined Yemen's ability to battle al-Qaeda's Yemeni affiliate, al-Qaeda in the Arabian Peninsula, and the Houthis' push into predominantly Sunni areas has boosted local support for the armed group.

Source: Al Jazeera and agencies