Street fighting raged across the Yemeni capital today after a tenuous truce broke down between tribal groups and forces loyal to President Ali Abdullah Saleh, edging the impoverished Arab country closer to civil war.
UN human rights chief Navi Pillay said his office had received as yet not fully confirmed reports that more than 50 people had been killed by Yemeni government forces since Sunday.
Global powers have been pressing Mr Saleh to sign a Gulf-led deal to hand over power to try to stem the growing chaos in Yemen, home to al-Qaeda militants and neighbour to the world's biggest oil exporter, Saudi Arabia.
"The ceasefire agreement has ended," a government official said today.
The weekend agreement took effect after more than 115 people were killed when the two sides battled with machine guns, mortars and rocket propelled grenades during fights in capital city in Sanaa.
Global powers have been pressing Mr Saleh to sign a Gulf-led deal to handover power aimed at stemming the growing chaos in Yemen, home to al-Qaeda militants and neighbour to the world's biggest oil exporter, Saudi Arabia.
A UN human rights official said today that more than 50 protesters have been killed in the Yemeni city of Taiz since Sunday by troops trying to crush their anti-government rallies.
"The UN human rights office has received reports, which remain to be fully verified, that more than 50 people have been killed since Sunday in Taiz by Yemeni Army, Republican Guards and other government-affiliated elements," UN human rights chief Navi Pillay said in an internet posting monitored in Dubai.
Government troops and locals have also been trying to force al-Qaeda and Islamists militants from the southern city of Zinjibar after they seized the coastal town at the weekend.
The United States and Saudi Arabia, both targets of attacks by Yemen-based al-Qaeda in the Arabian Peninsula, are worried that chaos is emboldening the group.
Opposition leaders have accused Mr Saleh of deliberately allowing Zinjibar, near a sea lane where about 3 million barrels of oil pass daily, to fall to al-Qaeda in a bid to show how chaotic Yemen would be without him.
Opposition groups made up of tribal leaders, Islamists and leftists have said they could do a far better job of curtailing the al-Qaeda threat.
At least 320 people have been killed in various fighting in Yemen since protests calling for Mr Saleh to end his nearly 33 year rule started about four months ago, inspired by the popular uprisings that ended the reign of the long-standing rulers of Tunisia and Egypt.
Under Mr Saleh, Yemen has moved to the brink of financial collapse, with about 40 percent of the population living on less than $2 a day and a third facing chronic hunger.
Reuters