SANAA, Yemen -- UN-sponsored talks between Yemeni political parties and Shiite rebels who occupy the capital broke down Sunday, with several main factions calling for renewed protests against the rebels.

The failure extended a power vacuum in the leaderless country, home to what Washington considers al-Qaida's most dangerous offshoot, after the president resigned last week while rebels surrounded his house and demanded concessions.

An official with the leadership of a party present at Sunday's meeting says the Islamist Islah party pulled out of the talks along with the Socialist and Nasserite parties. The official says the group rejects dialogue with the rebels, known as Houthis, and calls for peaceful protests against them.

The parties demand the release of a group of 11 activists and journalists the Houthis detained earlier in the day during protests against them in Sanaa.

The Houthis, who control the streets of the capital in the absence of significant central government forces, had scuffled with the demonstrators, firing automatic rifles into the air to disperse the crowd and breaking journalists' cameras.

At another anti-rebel protest Sunday in the capital, some 200 demonstrators gathered in Change Square and marched toward the presidential palace. The square was the birthplace of Yemen's 2011 uprising against longtime autocrat Ali Abdullah Saleh.

By nightfall, the streets were clear and the city silent. Just a day earlier, tens of thousands of people marched across the country to denounce the rebels, mainly adherents of a Shiite sect who swept down from their northern strongholds last summer.

They control several cities and say they are fighting corruption and want a greater share of power, including more influence over the writing of a new constitution.

Earlier, state news agency SABA reported that parliament had postponed a meeting which had been scheduled for Sunday to decide on whether to accept the resignation of Abed Rabbo Mansour Hadi, who quit as president Thursday along with his Cabinet.

Hadi remains at his private residence, surrounded by Houthi forces who run checkpoints across the capital and patrol the streets in pickups mounted with machine-guns.

Houthis also surrounded the headquarters building of the country's air force on Sunday, the officials added, preventing its top officer from entering.

Elsewhere in Sanaa, a car bomb exploded, injuring 5 people including one seriously, security officials said.

Meanwhile, officials with the office of UN envoy Jamal Benomar say he is continuing his efforts to forge an agreement between the different Yemeni political forces.

All officials spoke on condition of anonymity because they were not authorized to release the information otherwise.