More than 50 countries, led by Switzerland, will ask the United Nations Security Council Monday to refer Syria to the International Criminal Court, a move that would pave the way for war crimes prosecutions.

A letter obtained by the Associated Press cites the findings of a U.N. expert panel documenting torture, sexual violence and summary executions that have occurred in Syria since the start of the uprising in March 2011.

The violence continued Sunday as Syrian fighter jets bombed the Damascus suburbs, killing at least nine people, including a number of children, in a government offensive to dislodge rebels from strategic areas around the capital.

A report by the opposition Damascus Media Center cited as many as 36 people killed in the attack, including 14 children. That account could not be independently confirmed.

The Britain-based Syrian Observatory for Human Rights said the deaths occurred when a shell exploded in the eastern Ghouta district on the outskirts of the capital.

Video footage showed women weeping near the dismembered bodies of children lying in a muddy field near an air base on the edge of the town of Muleiha.

A member of the group said Syrian President Bashar al-Assad's forces were targeting civilian areas to try to weaken support for the rebels.

Rebels have been attacking the Muleiha base for days and the army has fired hundreds of rockets on the town in response.

Clashes also raged around army bases and airfields in northern Syria.

Meanwhile, Russia urged the rebels to make counter-proposals to those made by Mr. Assad in a recent speech to start a dialogue that could end the fighting.

Foreign Minister Sergei Lavrov said Sunday that if he were “in the opposition's place,” he would come up with ideas in response on how to establish a dialogue.

He repeated Russia's position that the opposition's demand for Mr. Assad to quit could not be a precondition for peace talks to end the 21-month conflict that has killed at least 60,000 people.