The United Nations envoy to Yemen says a national dialogue to resolve the country's crisis will resume on Monday, three days after Houthi fighters took power in a move widely condemned as a "coup".

Jamal Benomar said on Sunday that all of the country's political factions, including the Houthis, would participate.

"Following consultations with all political sides and direct contact with Abdel-Malik al-Houthi, I am pleased to inform you that the parties have agreed to resume the negotiations aimed at reaching a political solution to the current crisis," Benomar said on his official Facebook page.

The Houthis dissolved parliament on Friday and created a "presidential council" in a move designed to fill a power vacuum after President Abd-Rabbu Mansour Hadi and Prime Minister Khalid Bahah resigned last month.

The Houthis said they will set up a national council of 551 members to replace the country's existing legislature.

Meanwhile, speaking in Saudi Arabia, UN Secretary General Ban Ki-Moon said the situation was "seriously deteriorating", before he called for Hadi to be restored as president.

Arab League chief Nabil el-Araby branded the Houthi move as a "coup against constitutional legitimacy to impose that group's will at gunpoint".

Tensions remain high in the south and southeast, where authorities said they did "not recognise" the rule of the Houthis and that they "totally reject the constitutional declaration" under which they seized control.

Yemen coup: What happens now?

In the oil-rich eastern province of Maarib, which the Houthis have long been eyeing, deputy governor Abdelwahid Namran told the AFP news agency that Sunni tribesmen were "discussing means of facing any developments".

The Houthi takeover has also stoked secessionist sentiments in the south, raising fears of a repeat of the 1994 civil war, when the formerly independent south attempted to break away from its union with the north, forged four years earlier.