SANAA (Reuters) - Saudi Arabia has brokered a fresh truce between a powerful Yemeni tribal federation and forces loyal to President Ali Abdullah Saleh, a Saudi source said on Saturday, and a tribal leader said his followers were abiding by it.
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 since the uprising against Saleh's 32-year role began.
Broadcasters Al Jazeera and Al Arabiya, citing Yemeni and Saudi sources, said Saleh was on his way to Saudi Arabia for medical treatment, a day after suffering head wounds in a shelling attack on a mosque in the presidential compound, but Yemen's deputy information minsiter denied the reports.
Seven people were killed when what appeared to be rockets hit the presidential palace and several government officials were wounded. Saleh blamed a tribal federation for the assault.
"The rocket was devastating. It was a clear assassination attempt against the president," said Abdulla Ali al-Radhi, Yemen's ambassador to the United Kingdom.
The BBC reported that the attack left Saleh with shrapnel near his heart and second-degree burns to his chest and face. It said sources close to the president had told the broadcaster Saleh had a piece of shrapnel almost 7.6 cm long under his heart.
Four months into a deadly revolt, 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 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 said 10 tribesmen were killed and dozens injured while denying responsibility for the palace attack.
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 the 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 33-year 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.
A Yemeni official told Reuters that Saleh "had suffered minor wounds to his head and I believe his face."
"It's not easy for the president. He has lost people close to him and who were sitting next to him when it happened," the official said.
Saleh has exasperated his former U.S. and Saudi allies, who once saw him as a key partner in efforts to combat Yemen-based al Qaeda in the Arabian Peninsula (AQAP).
Defying world pressure, Saleh has thrice reneged on a deal brokered by Gulf states for him to quit in return for immunity from prosecution, even as he haemorrhages support at home.
Residents in Sanaa faced worsening fears after 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.
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 U.N. human rights chief was checking reports that more than 50 people had been killed in Taiz since Sunday.
Nearly 200 people have been killed in the capital in the past two weeks as street battles 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 violence that has engulfed more of the city.
"Bullets are everywhere, explosions terrified us. There's no chance to stay any more," said Sanaa resident Ali Ahmed.
Spain said it was evacuating its citizens and diplomats in Yemen, while Germany ordered the temporary closure of its embassy, adding to the number of countries shutting the doors on their diplomatic missions in Sanaa due to the fighting.
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.
(Additional reporting by Mohammed al-Ramahi in Sanaa, Mohammed Mukhashaf in Aden, Khaled al-Mahdi in Taiz, Mahmoud Habboush in Dubai, Samia Nakhoul in London, Erik Kirschbaum in Berlin and the Madrid bureau; writing by Jon Herskovitz; editing by Tim Paerce)