“The Government has an international legal obligation to protect peaceful demonstrators and the right to peaceful protest,” High Commissioner for Human Rights Navi Pillay said in a statement.

“The first step now is to immediately halt the use of violence,” she said, calling for am end to the use of live ammunition by security forces against peaceful protestors.

Pillay’s call came as thousands of Syrian troops backed by tanks on Monday launched assaults on the flashpoint towns of Daraa and Douma, firing indiscriminately and leaving bodies in the streets, witnesses said.

Syria has been cracking down on anti-regime protests across the country, killing more than 135 people and arresting scores since Friday, according to rights activists and witnesses .

The crackdown comes despite President Bashar al-Assad signing on Thursday decrees ending a draconian state of emergency, imposed by the Baath Party when it seized power in 1963, to placate more than a month of pro-democracy protests.

Pillay called the Syrian government’s response to the demonstrations erratic.

“Just a few days after the announcement of sweeping and important reforms, we are seeing such disregard for human life by Syrian security forces,” she said.

Pillay noted that the president had instructed security forces not to resort to violence against demonstrators but the excessive use of force has only intensified in recent days.

“The violence and ongoing repression of activists, however, indicates that either the Government is not serious about those reforms or it is unable to control its own security forces,” said the UN human rights chief.

“I strongly urge President Al-Assad and his Government to rapidly implement promised reforms to restore the people’s confidence,” she said.

Pillay said her office had received a list naming 76 people who were killed on Friday during evidently peaceful marches, but that the number may be considerably higher, and that her staff was looking into the reported killing of at least 13 others in funeral processions on Saturday.