Seven people were killed in an attack on the presidential palace on Friday that wounded Saleh, who is facing mounting domestic and regional pressure to end his three-decade rule. It is not clear who would govern Yemen if, indeed, he left a country Western governments view with concern as a major base for operations by al Qaeda. The prime minister, two deputy prime ministers and the speakers of both parliamentary chambers are being treated in Riyadh for injuries.
Leaving Yemen at a time of such instability, even for medical care, could make it hard for Saleh to retain power and be seen as the first step in a transfer of leadership. A Saudi official said earlier that Saudi Arabia, which shares a border with Yemen, had brokered a fresh truce between a powerful Yemeni tribal federation and forces loyal to Saleh, and a tribal leader said his followers were abiding by it.
The cease-fire appeared to be holding on Saturday night and the streets of Sanaa were quiet. A Saudi-brokered truce agreed a week ago held for only a day before fresh street battles broke out in the capital Sanaa, leading to the most intense fighting there in the four-month-old uprising against Saleh's rule.
Abdulla Ali al-Radhi, Yemen's ambassador to Britain, said of Friday's attack on the palace "The rocket was devastating. It was a clear assassination attempt against the president. The BBC, quoting sources close to Saleh, said the attack had left the president with a 7.6 cm long piece of shrapnel under his heart and second-degree burns to his chest and face.
Worries are mounting that Yemen, already on the brink of financial ruin and home to al Qaeda militants, could become a failed state that poses a threat to the world's top oil exporting region and to global security. Saleh's forces retaliated over the attack by shelling the homes of the leaders of the Hashed tribal federation, which has been engaged in street fights with his forces. Spokesmen for the group denied responsibility for the palace attack and said 10 tribesmen were killed and dozens injured by the shelling.
A growing number of people in Saleh's inner circle feel the attack may have carried out by General Ali Mohsen who has broken from Saleh, sided with anti-government protesters and called the president a "madman who is thirsty for more bloodshed". An expert on Yemen with close ties to Sanaa's leadership said: "Nobody could have done this with such military precision other than a military man."
Global powers have been pressing Saleh to sign a Gulf-brokered deal to end his rule. Leaving Yemen, even for medical care, would make it hard for Saleh to retain power and could be seen as the first step in a transfer of leadership.
He has exasperated his former US and Saudi allies, who once saw him as a key partner in efforts to combat Yemen-based al Qaeda in the Arabian Peninsula (AQAP), by repeatedly reneging on a deal brokered by Gulf states for him to quit in return for immunity from prosecution.
Tensions in the flashpoint of Taiz, about 200 km (120 miles) south, eased after police and military units withdrew from the city following a week of clashes with pro-reform demonstrators that left dozens dead. The UN human rights chief was checking reports that more than 50 people had been killed in Taiz since Sunday.
Fighting between the Hashed tribal federation and Saleh's forces spread to new parts of the divided capital on Friday, prompting a fresh exodus of war-weary civilians. Nearly 200 people have been killed in Sanaa in the past two weeks as fighters using machineguns, mortars and rocket propelled grenades shuttered shops and forced Sanaa's airport to ground flights twice.
Sanaa roads were clogged when the sun rose by civilians fleeing the violence. "Bullets are everywhere, explosions terrified us. There's no chance to stay any more," said Sanaa resident Ali Ahmed. At least 420 people have been killed since the uprising against Saleh began in January, inspired by the movements in Tunisia and Egypt that toppled their long-standing leaders.
The battles are being fought on several fronts, with popular protests in several cities and military units breaking away from Saleh to protect the protesters. There has also been a week-long campaign in Zinjibar by locals and Saleh's soldiers to oust Islamist and al Qaeda militants who seized the southern coastal city near a shipping lane where about 3 million barrels of oil pass daily.