Yemeni government forces opened fire Tuesday on protesters in Sanaa, killing 12 and injuring more than 70, a medical official said, a day after the capital witnessed its worst fighting in weeks.
Mohammed al-Qubati, the director of a field hospital at the main protest site in Sanaa dubbed "Change Square," said more than 70 protesters were injured in the protests demanding the resignation of President Ali Abdullah Saleh.
Tens of thousands of protesters marched through Sanaa, led by shirtless young men with the words "Leave ... you butcher" scrawled across their chests, referring to Saleh, .
Soldiers from the Republican Guard, a loyalist unit led by Saleh's son Ahmed, arrested four female protesters who were ahead of the main demonstration, said activist Habib al-Uraiqi.
Abdel-Rahman Berman of Yemen's National Organization for Defending Rights and Freedoms (HOOD) said Saleh's forces used live ammunition and harsh tear gas.
Berman said HOOD team monitoring the situation charged that government forces and thugs abducted female protesters and some wounded demonstrators in a "shameful and criminal way."
Similar demonstrations were held in other parts of Yemen, including the southern cities of Aden and Taiz, protest organizers said.
The protesters called for Saleh to be put on trial for killing demonstrators and urged the international community and the U.N. Security Council to help topple him.
On Tuesday, key members of the Security Council began considering a British-drafted resolution that would call for an immediate cease-fire in Yemen and transfer of power, as well as immediate action by Yemeni authorities to end attacks against civilians. The consultations are still in progress.
President Saleh is accused by many Yemenis of pushing the country into civil war by tenaciously clinging to power in the face of eight months of mass protests across the country, the defection to the opposition of key tribal and military allies and mounting international pressure on him to step down.
He has balked at a U.S.-backed plan proposed by Saudi Arabia and its five smaller allies in the Gulf Cooperation Council to hand over power to his deputy and step down in exchange for immunity.
Pre-dawn fighting between troops loyal to Yemen's embattled leader and rival forces killed at least 18 people in Sanaa on Monday, reviving fears of civil war in the poor Arabian peninsula nation.
A civil war would significantly hurt efforts led by the U.S. to fight Yemen's dangerous al-Qaida branch. It could turn Yemen into a global haven for militants just a short distance away from the vast oil fields of the Gulf and the key shipping lanes in the Arabian and Red Seas to and from the Suez Canal.
Associated Press writer Edith M. Lederer contributed to this report.