Protesters kept up the heat on President Ali Abdullah Saleh on Saturday as deaths mounted in the flashpoint city of Taez, even as a dissident general denied aiming to replace the Yemeni leader.
On the regional scene, Yemen recalled its ambassador to Qatar, state news agency Saba announced, after a call from the Gulf state for Saleh to step down stirred anger in Sanaa.
And the army shelled a suspected Al-Qaeda refuge in southern Yemen, after the United States expressed concern that pressure on the militant group had eased amid months of protests calling for the president's departure.
Thousands of protesters massed in Al-Hurriya (Liberty) Square in Taez, south of Sanaa, calling for those behind the deadly shooting of protesters to be held to account and for Saleh to go.
Medics said Yemeni security forces shot dead four protesters and wounded 116 in the flashpoint city in clashes that erupted on Friday and carried on into the next morning.
Apart from those killed or wounded by gunfire, 650 people suffered from tear gas inhalation, according to medics at a field hospital set up near Al-Hurriya Square.
Clashes lasted until about 3:00 am on Saturday (0000 GMT), with protesters trying to take over a provincial government building near the square, witnesses said.
In another bastion of opposition to Saleh, a protest strike paralysed southern Yemen's main city of Aden, where shops were shuttered in many districts, roads were cut off and public transport ground to a halt.
Meanwhile, General Ali Mohsen al-Ahmar, who has sided with anti-regime demonstrators and accused regime supporters of trying to kill him, denied having his sights set on political power.
Ahmar, who commands Yemen's northwest military district including Sanaa, pledged in late March to defend the protesters, who have pressed since January for Saleh's ouster.
"The army will be under the control of civilians, and I do not seek any position of power," Ahmar told an envoy of UN chief Ban Ki-moon, according to an overnight statement from the general's office.
"The army has merely responded to the call of the people who wished to protect the protesters from killings, repression and terror exercised by the regime, certain security services and the Republican Guard," Ahmar said.
Ahmar and other generals, top tribal and religious leaders and a number of other officials have defected, but key parts of the security forces commanded by Saleh's family members, such as the Republican Guard, have remained loyal.
Yemen's foreign ministry, quoted by Saba, said Sanaa's ambassador to Doha was "recalled for consultations following remarks by... (Qatari Prime Minister) Sheikh Hamad bin Jassim bin Jabr al-Thani."
Sheikh Hamad said on Thursday that Yemen's Arab neighbours in the Gulf "hope to reach a deal with the Yemeni president to step down," a position which Saleh slammed as a case of "blatant interference in Yemeni affairs."
Saleh on Friday telephoned Gulf Cooperation Council leaders, Yemen's embassy to Washington said in a statement, listing all the calls, with Qatar's Emir Hamad bin Khalifa al-Thani the only name missing.
The United States, which has cooperated closely with Saleh in its battle against Al-Qaeda, on Friday urged all sides in Yemen to engage in an "urgently needed dialogue" on a political transition.
Washington has expressed concern that Al-Qaeda militants could take advantage of unrest in Yemen, and that pressure from the impoverished country on the group has let up.
On Saturday, an officer from Yemen's 25th mechanised brigade said army units had begun shelling the Joar area in Abyan province, where Al-Qaeda militants were believed to have taken refuge.
The attack came two days after US Defence Secretary Robert Gates said Yemen had since the outbreak of its political crisis "really eased up the pressure on Al-Qaeda in the Arabian Peninsula," referring to the group's local affiliate.