Yemen's Houthi rebels welcomed on Thursday proposed concessions by the government on power-sharing but their gunmen still held positions outside the residence of President Abd-Rabbu Mansour Hadi, who remains a virtual prisoner there.

Hadi said on Wednesday he was ready to accept Houthi demands which also include constitutional change, yielding to pressure from the Shi'ite group whose fighters battled their way into the presidential palace this week, after seizing an aide to the president.

A Houthi politburo member said Hadi's concessions were in line with a peace deal which his group, whose official name is Ansarullah, signed with other political parties when they seized the capital Sanaa in September - a move that helped to cement the rebels' position as Yemen's de facto powerbrokers.

"The latest agreement is a series of timed measures to implement the peace and partnership accord, which shows that Ansarullah were not planning to undermine the political process," politburo member Mohammed al-Bukhaiti told Reuters.

"The agreement is satisfactory because it confirms what is most important in the partnership agreement," he said.

The withdrawal of the gunmen, and the release of presidential aide Ahmed Awad bin Mubarak could happen in the next three days if the authorities committed to implementing the agreement fully, al-Bukhaiti added.

The rebels' rise to influence has caused chaos in Yemen and resulted in a shift in its complex web of tribal, religious and regional allegiances. In addition, the Houthis are players in a regional struggle between neighboring Saudi Arabia and Shi'ite Iran.

Suspecting Iranian complicity, the Sunni Muslim authorities in Riyadh cut most of their financial aid to Yemen after the Houthis' takeover of the capital.

Hadi said on Wednesday he was ready to accept demands for constitutional change and power sharing with the Houthis. Conceding to a major demand, he confirmed in a statement that the draft constitution was subject to amendment and said all sides had agreed that government and state institutions, schools and universities should rapidly return to work.

He also said the Houthis had agreed to leave his private residence and the presidential palace, and to free bin Mubarak, a former presidential nominee whom the Houthis seized on Saturday during a standoff.

But the capital remained largely shut down, witnesses said, even though the airport and seaport in the southern city of Aden resumed work on Thursday, having closed for a day in protest at the Houthi offensive against Hadi's administration.

STAYING PUT

Clusters of Houthi fighters were dotted around the perimeter of the presidential palace on Thursday. At Hadi's residence, sentry points normally used by presidential guards were empty, and a group of Houthis with an army vehicle were parked at a main entrance.

"The Houthis will not withdraw. They have agreed in the past to withdraw from Sanaa, but they did not," said Mohammed Said, a local resident standing close to Hadi's residence.

Said he thought they would procrastinate to achieve more demands and then get ready to take control of Marib, an oil-rich province east of Sanaa, where al Qaeda operates.

Another Houthi official told Reuters he expected Hadi to announce a decision on government posts, after which the group would begin procedures for the release of bin Mubarak and the gradual withdrawal from the presidential buildings.

"And the complete withdrawal will coincide with the completion of all the decisions related to the deal signed yesterday," the Houthi official said, declining to be identified.

But Yemen's Information Minister Nadia al-Saqqaf expressed scepticism over the Houthi's intentions. "Ahmed Mubarak is still (the) Houthis' hostage," she wrote on her Twitter account. "They got what they want. Why they should fulfill their promise?"

A source close to the presidency said the Houthis have "gradually" begun to withdraw from Hadi's private residence. "Presidential security will be redeployed to their positions in the next two days," the source told Reuters.