“Saleh underwent a few other minimally invasive procedures and non-invasive treatment for his injuries during the last two days,” said the source.

The source said all necessary medical procedures had been employed to “assess body functions with an aim to ensure quick recovery and to treat the burn injuries.”

The source also said the president was “out of danger and responding to medical treatment satisfactorily.”

Yemen’s acting leader, Vice President Abd-Rabbu Mansour Hadi, has said Saleh intends to return within days.

Reuters reported on Tuesday that President Saleh was more seriously injured in the rocket attack than thought. Saleh suffered 40 percent burns and has bleeding inside his skull, the news agency said, citing an unidentified Yemeni official.

Given the pain involved with burns and the process of healing, Saleh would probably require strong sedation and a few more days to heal, said the Riyadh hospital source.

There have also been reports that one of the wooden shards that sliced into his body punctured a lung, Abdul Rahman Al-Rashed, the head of the Arabiya television network, was quoted as saying in a report Tuesday.

That too could require a more extended convalescent period, hampering any plan for president to go back to Sanaa, he said.

With the admission of Saleh and a number of top Yemeni officials to hospitals in Riyadh for treatment, the focus of attention of stakeholders and peace negotiators has also shifted to Riyadh.

A Gulf Cooperation Council (GCC) spokesman said a meeting of its foreign ministers would be held Tuesday in Jeddah to discuss the situation in Yemen.

British Foreign Secretary William Hague called Tuesday for Yemen to begin an immediate political transition, heaping pressure on the embattled president to cede power.

Hague’s remarks came a day after Washington called for an “immediate transition” of power after President Saleh arrived in Saudi Arabia.

In Sanaa, thousands of protesters gathered Tuesday in front of the Yemeni vice president’s residence, demanding the acting leader form a transitional council to create a new government.

Sanaa Gov. Nouman Duweid remains in a coma, Tareq Shami, the spokesman for the General People’s Congress, was quoted as saying in a report.

Yemen’s army, meanwhile, said it had killed dozens of militants including a local Al-Qaeda leader in the southern town of Zinjibar, capital of the flashpoint Abyan province.

A local official said 15 soldiers had been killed in the battles for control of the town seized by militants some 10 days ago.

The fighting has reduced Zinjibar, once home to more than 50,000 people, to a ghost town without power or running water.

Fighting also flared again in the city of Taiz, south of Sanaa, where anti-government gunmen have clashed sporadically with troops in the past few days.