Syria’s allies in Russia called for urgent talks Thursday between the Damascus government and the opposition, saying an attack by Syrian renegade troops on a government building resembles the start of a civil war.

President Bashar al-Assad is facing severe international isolation stemming from his crackdown on an eight-month-old uprising, which the United Nations estimates has killed 3,500 people. The Arab League confirmed suspension of its membership Wednesday and issued a three-day deadline Wednesday for it to stop the violence or face unspecified sanctions.

Activists said at least nine civilians, including a child, were killed by security forces on Thursday.

“This is all looking very much like a civil war,” Russian Foreign Minister Sergey Lavrov told reporters in Moscow, referring to a pre-dawn attack in the Damascus suburb of Harasta on ednesday by the Free Syrian Army, a group of army defectors determined to bring down the regime.

Wednesday’s attack could not be independently confirmed, and the Free Syrian Army released no details about the fighting or possible casualties.

The army defectors reportedly fired machine guns and rockets at an Air Force Intelligence base just outside Damascus, sending a strong signal that the popular uprising could descend into an armed conflict.

On Thursday, the dissident group reportedly staged another attack, firing rocket-propelled grenades on ruling Baath party offices housing security agents in the town of Maaret al-Numan, near the border with Turkey.

Rami Abdul-Rahman, director of the Britain-based Syrian Observatory for Human Rights, said clashes broke out but there was no immediate word on casualties.

Lavrov urged Syrian and opposition forces alike to cease violence and negotiate, but he reserved his harshest words for the opposition.

“It is not a secret that along with the peaceful demonstrators, whose strivings and demands we support, there is more and more participation from groups of armed people who have an entirely different agenda from reform and democracy in Syria,” he said. “Their agenda concerns ethnic and tribal interests, and these people have received and are continuing to receive weapons in growing amounts from neighboring countries, and they don’t particularly hide it.

“Weapons are being smuggled in through Lebanon, Iraq, Afghanistan, Jordan, and if the opposition uses such methods, this will lead to a full-scale civil war,” Lavrov said.

— Associated Press