|President Saleh says he is "well and in good health" after surviving an attack on his presidential palace [Al Jazeera]
Ali Abdullah Saleh, the Yemeni president, says he is "well and in good health" after suffering injuries in an attack on his presidential palace in the capital, Sanaa.
In an audio address delivered on state television late on Friday night, Saleh said the strike, where "seven officers were martyred", was by an "outlaw gang" - the opposition Hashed tribe led by powerful Sadiq al-Ahmar.
Shells hit a mosque in the presidential palace compound where officials, including Saleh, were praying.
At least three guards and Sheikh Ali Mohsen al-Matari, an imam at the presidential compound's mosque, died and "several other officials and officers" were wounded, Yemen's state news agency SABA said.
The president was taken to the defence ministry hospital to be treated for his minor injuries, officials said.
"I salute our armed forces and the security forces for standing up firmly to confront this challenge by an outlaw gang that has nothing to do with the so-called youth revolution," Saleh said in his late night audio address.
The president, who has faced nationwide protests against his 33-year rule since January, was scheduled to address the nation earlier in the day. His appearance was postponed for several hours until his audio speech on Friday night.
Initial reports of the palace attack hinted at Saleh's possible death, to which the Yemeni state television said - as an assurance to the public - that the president was "well".
Abdu al-Jandi, the deputy minister of information, has said, "There is nothing that affects his health," while mentioning that a probe on Friday's violence at the palace has been launched.
The blame game
Authorities blamed the shelling on dissident tribesmen loyal to Sheikh Sadiq al-Ahmar who have been locked in fierce clashes with government forces in Sanaa since Tuesday.
"The prime minister, head of the parliament and several other officials who attended the Friday prayers in the mosque at the presidential palace were wounded in the attack," Tareq al-Shami, spokesman for the ruling General People's Congress, told the AFP news agency.
"The Ahmar (tribe) have crossed all red lines," he added.
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.
"[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, of the attack's possible message.
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.
Tribal home 'shelled'
Friday's attack came soon after Yemeni troops, who have deployed heavy weaponry in their battle against the tribesmen, sent a shell crashing into the home of Sheikh Hamid al-Ahmar, a leader of the biggest opposition party and brother of Sheikh Sadiq.
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Three shells also struck near the university campus in the city centre where opponents of Saleh have been holding a sit-in for four months demanding his exit.
After a brief lull at dawn, artillery and heavy machine-gun fire rocked the al-Hassaba neighbourhood of northern Sanaa where Sheikh Sadiq has his base, witnesses said.
They said that during the fighting the headquarters of national airline Yemenia was burnt down and the offices of Suhail TV, a channel controlled by Sheikh Sadiq, destroyed.
There was no immediate word on casualties from the latest fighting as medics said ambulance crews were unable to access the battlegrounds.
Before the attack on the palace, protesters paraded the coffins of people they said were killed by Saleh's forces.
Heavy fighting also spread for the first time to the southern part of Sanaa, an area held by forces loyal to Saleh, and possibly marking a turning point in the conflict.
Explosions were heard in the southern city of Taiz, where the United Nations has said it is investigating reports that 50 people have been killed since Sunday.
The White House expressed its concern amid the fighting on Friday. It urged "calm and restraint on all sides" in Yemen, and called for the dispute to be resolved through negotiations, Tommy Vietor, US National Security Council spokesman, said.
Vietor added that John Brennan, US president Barack Obama's top counter-terrorism adviser, had travelled to Saudi Arabia and the United Arab Emirates "to discuss options with government officials on how to address Yemen's deteriorating situation".
Mark Toner, the state department's deputy spokesman, also denounced Friday's violence and made a call for an immediate ceasefire.
"We strongly condemn all these senseless acts of violence that have taken place in the last 24 hours, and call for an immediate cessation of all hostilities," Toner said.
"All parties must end these attacks and avoid any further escalation or any further casualties in the days ahead."
"Clearly the deteriorating situation in Yemen can be only addressed through a peaceful and orderly transfer of power and so we again call on president Saleh to move immediately to heed the calls of the Yemeni people," he added.