Ali Abdullah Saleh has reportedly flown to Saudi Arabia for medical treatment, a day after his compound is attacked.
There are conflicting reports about the whereabouts of Yemen's president, a day after he was injured in an attack on his compound.
Some reports suggested Ali Abdullah Saleh was on his way to Saudi Arabia for medical treatment on Saturday evening, but sources told Al Jazeera that the president was being treated for face burns at a hospital in Sanaa.
Reports said Saleh was treated by a team of Saudi plastic surgeons and that a Saudi aircraft was ready to take him to Saudi Arabia if needed.
Earlier, Reuters news agency quoted a Saudi official as saying Saleh was on his way to Saudi Arabia.
However, Reuters quoted a Saudi source as saying that the president had arrived in Saudi Arabia.
The Associated Press said Saleh had accepted Abdullah's offer to travel to the country.
Meanwhile, sources told Al Jazeera that Vice-President Abd-Rabbu Mansour Hadi has taken over as acting president and supreme commander of the armed forces.
Earlier on Saturday, sources said a powerful Yemeni tribal federation battling Saleh's security forces and forces loyal to him agreed to abide to a Saudi-brokered one-week truce.
Abdullah intervened shortly after Saleh's presidential palace compound in Sanaa, was hit by a rocket attack on Friday. A government official said 11 people were killed in the shelling.
The prime minister, two deputy prime ministers and the speakers of both parliamentary chambers are
Shells hit a mosque in the presidential palace compound on Friday as officials, including Saleh, were praying.
The British broadcaster BBC quoted unnamed sources as saying Saleh was suffering from a piece of shrapnel under his heart and second-degree chest and face burns.
Mohammed Iljendi, the Yemeni deputy minister of information, told Al Jazeera that Saleh had been injured but that "his health is fine and there is nothing to be concerned about".
He denied reports that Saleh was seeking medical treatment in Saudi Arabia.
Hisham Sharaf, minister of trade and industry, said he met Saleh on Friday night and that the president remained defiant in the face of escalating violence.
"He was in very high morale. The strike that doesn't break you makes you stronger. The strike made him more adamant that he won't hand over the country until he is sure it will be safe and clear of militias," Sharaf said.
In an audio address delivered on state television late on Friday night, Saleh said the attack was carried out by an "outlaw gang", referring to the Hashed tribal federation led by Sadiq al-Ahmar, a powerful dissident tribesman.
Al-Ahmar's fighters have been battling government forces in the capital since a truce crumbled on Tuesday.
Witnesses said sporadic shelling and rocketfire on Saturday rattled the al-Hasaba district of northern Sanaa where al-Ahmar has his base, forcing residents to flee. The area is suffering from water and electricity cuts.
Elsewhere in Yemen, officials said police and military units have withdrawn from the southern city of Taiz after a week of clashes with pro-reform demonstrators that left dozens dead.
"Looting and scenes of chaos are spreading after the withdrawal of security forces and the army from the city," the opposition leader, who asked not to be named, told Reuters news agency.
Tareq al-Shami, a ruling party official, confirmed the government's security forces had pulled back from the city which is about 200km south of the capital.
The UN human rights chief said her office was investigating reports that as many as 50 have been killed in Taiz since Sunday.
Abdul Ghani al-Iryani, an independent political analyst in Sanaa, told Al Jazeera that it was "quite reasonable to assume" that al-Ahmar's fighters were behind the palace hit on Friday.
"[The tribesmen] probably wanted him to know that [Saleh] can no longer attack them with impunity, and that they can reach him as he can reach them," al-Iryani said.
But al-Ahmar's office denied responsibility and instead blamed Saleh for the attack, calling it part of his effort to help justify a government escalation of street fighting in the capital.
Ten people were killed and 35 others injured in southern Sanaa on Friday as Yemeni troops shelled the home of Hamid al-Ahmar, the brother of Sadiq al-Ahmar, Hamid's office said on Saturday.
Hamid, a prominent businessman, is a leader of Yemen's biggest opposition party, Al-Islah (reform).
The shelling in Hada neighbourhood also targeted the homes of Sadiq's two other brothers, Hemyar and Mizhij, and that of Ali Mohsen al-Ahmar, a dissident army general.
The US has condemned Friday's violence, including the attack on the Saleh's palace, and called for him to transfer power.
"We call on all sides to cease hostilities immediately and to pursue an orderly and peaceful process of transferring political power as called for in the GCC-brokered agreement," the White House said, referring to the Gulf Co-operation Council.
Yemen's parliamentary opposition on Saturday called for an "immediate" ceasefire.
The Common Forum alliance condemned what it said was the "the dangerous twist which the clashes have taken in targeting the homes of citizens, the presidential palace, and vital installations".
The alliance of parliamentary opposition groups urged "quick action" from the international community "to save Yemen and its people from falling into [civil] war", in the statement.
Meanwhile, Germany said it had ordered the immediate closure of its embassy in Yemen "because of current developments."
"The embassy team that is still on the ground will leave the country as soon as it is possible and safe," the foreign ministry said in a statement.
Al Jazeera and agencies