A fragile truce broke down between tribal groups and forces loyal to Yemeni President Ali Abdullah Saleh on Tuesday. Renewed clashes have been reported in Sanaa between government troops and followers of the country's most powerful tribal leader, Sheik Sadeq al-Ahmar.
Security forces have also reportedly fired on protesters rallying against the violent crackdown in the southern Yemeni city of Taiz. Troops have killed more than 50 people since Sunday as they crushed a four-month-long sit-in.
The UN High Commissioner for Human Rights, Navi Pillay, called for an end to the brutal fighting.
"Such reprehensible acts of violence and indiscriminate attacks on unarmed civilians by armed security officers must stop immediately," Pillay said in a statement on Tuesday.
The European Union's foreign policy chief, Catherine Ashton, also strongly criticized the violence being applied in Taiz.
"I am shocked and condemn in the strongest terms the use of force and live ammunition against peaceful protesters in the city of Taiz," Ashton said in a statement on Tuesday. "The continued repression by the Yemeni regime and grave violations of human rights and international humanitarian law cannot be accepted."
She said those responsible for these deeds needed to be held accountable.
But President Saleh continues to disregard calls not only from global leaders, but also from elements in his own military and tens of thousands of Yemeni protesters to end his nearly 33-year-rule.
Ashton said the time had come to sign a Gulf-led deal on political transition "without further pretexts." Pillay also stressed that the ongoing violence would only yield more insecurity, moving the country away from any sort of resolution.
"I urge all parties to continue efforts aimed at finding a peaceful solution to this conflict," Pillay said. "The bloodshed must stop."
Author: Sabina Casagrande (Reuters, dpa, AP, AFP)
Editor: Nicole Goebel