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 minister 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. The United States expressed concern Saturday at the Internet shutdown in Syria, warning the embattled regime that attempting to silence protesters "cannot prevent the transition currently taking place." "We are deeply concerned by reports that Internet service has been shut down across much of Syria, as have some mobile communication networks," Secretary of State Hillary Clinton said in a statement as deadly anti-government protests rage across the Middle Eastern nation. "We condemn any effort to suppress the Syrian people's exercise of their rights to free expression, assembly, and association," she added. Witnesses said Internet lines were cut in Damascus and the coastal city of Latakia on Friday, while a US-based Internet monitoring firm said about two-thirds of the country's networks had been cut off from access to the Web. Clinton noted that President Bashar al-Assad's government "has a history of restricting the Internet in an attempt to prevent the Syrian people from accessing and sharing information. 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.