The UN human rights office put the death toll in Taez since Sunday at more than 50 Deadly clashes erupted in the Yemeni capital on Tuesday shattering a truce between loyalist troops and dissident tribesmen as security forces shot dead seven protesters in the second-largest city of Taez .
European Union foreign policy chief Catherine Ashton voiced shock at the use of live rounds against protesters in Taez in a crackdown that the UN human rights office said had already killed more than 50 people since Sunday.
Fierce fighting erupted in the capital Sanaa before dawn between troops loyal to embattled President Ali Abdullah Saleh and fighters loyal to Yemen\'s most powerful tribal leader Sheikh Sadiq al-Ahmar, an AFP correspondent said.
A plume of dark smoke rose into the sky over Ahmar\'s compound in north Sanaa, witnesses said.
There were also heavy exchanges between his tribesmen and loyalist troops around the headquarters of the military police and the official Saba news agency, as well as in a major thoroughfare in the Yemeni capital, the correspondent said.
Three of Ahmar\'s fighters were killed in the clashes, a medic said. There was no immediate word of any casualties on the loyalist side.
Saleh\'s government accused Ahmar\'s fighters of breaking the truce which the tribal chief announced on Friday after four days of ferocious clashes.
The defence ministry\'s 26sep.net news website said that his tribesmen had seized both the headquarters of the ruling General People\'s Congress and the main offices of the water utility.
But sources close to Ahmar accused loyalist forces of breaking the truce by firing on his compound.
In Taez, south of Sanaa, loyalist security forces shot dead seven anti-government protesters on Tuesday, witnesses said, after 21 were killed as a long-running sit-in in a central square was smashed.
Five were killed in central Taez, witnesses said. Others clashed with police while trying to enter the city, leaving two protesters dead.
Witnesses said security forces were attempting to prevent anyone from gathering in Taez on Tuesday, firing on those who tried to do so.
Protesters have since January been calling for the departure of Saleh, in power since 1978.
Tuesday\'s deaths came after security forces smashed a four-month-long sit-in in Taez, killing 21 protesters.
The UN human rights office put the death toll in Taez since Sunday at more than 50 with hundreds more injured.
\"The UN human rights office has received reports... that more than 50 people have been killed since Sunday in Taez by Yemeni army, Republican Guards and other government-affiliated elements who forcibly destroyed the protest camp in Horriya Square using water cannons, bulldozers and live ammunition,\" it said in a statement released in Geneva.
\"Such reprehensible acts of violence and indiscriminate attacks on unarmed civilians by armed security officers must stop immediately,\" said UN human rights chief Navi Pillay.
The EU foreign policy chief said: \"I am shocked and condemn in the strongest terms the use of force and live ammunition against peaceful protesters in the city of Taez.
\"The continued repression by the Yemeni regime and grave violations of human rights and international humanitarian law cannot be accepted,\" Ashton added.
Saleh has been clinging to power despite mounting pressure from the international community to agree his departure from office.
The opposition has signed up to a deal brokered by impoverished Yemen\'s wealthy Gulf neighbours under which Saleh would hand power to the vice president within 30 days in return for a promise of immunity from prosecution.
The president initially agreed to the plan but then repeatedly set new conditions for signing it, prompting the six-nation Gulf Cooperation Council to suspend its mediation efforts.
In the south, suspected Al-Qaeda fighters killed four Yemeni soldiers and wounded 10 on Tuesday in an attack near the city of Zinjibar, a security official said, while a medic said two others had died of their wounds.
The hospital had on Monday received 40 soldiers wounded in Zinjibar fighting, some of whom were in a serious condition, the medic added.
A security official said on Sunday that suspected Al-Qaeda gunmen had taken control of most of Zinjibar, the capital of Abyan province.
Before Tuesday\'s attack, the defence ministry said 21 soldiers, including a number of officers, had been killed in the fighting.