Fifty-seven countries, led by Switzerland, are calling for the United Nations Security Council to refer the Syria conflict to the International Criminal Court for an investigation into war crimes.
The letter, sent on Monday to the 15-member Security Council, cites the findings of a U.N. panel documenting torture, sexual violence and summary executions that have occurred in Syria since the start of the uprising in March 2011.
It demands the Security Council open an ICC investigation "without exceptions and irrespective of the alleged perpetrators."
As the violence continues, humanitarian groups are calling on the international community to increase aid for refugees driven from their homes by the crisis.
The International Rescue Committee
issued a new report Monday warning that the region faces a "staggering humanitarian disaster." It outlines the challenges refugees face in accessing health care, as well as what it calls "horrific levels" of sexual violence that many families cited as their reason for fleeing Syria.
The group is urging donors to meet calls by the United Nations for $1.5 billion in funding, as well as other resources to help neighboring countries now housing thousands of Syrian refugees.
Selena Victor, advocacy director with the IRC, said even if the conflict in Syria ends, the effects of the fighting will leave a long-term, large-scale need for refugee and reconstruction aid.
"The needs are enormous - there are two million people who have been forced to flee their home, half a million refugees in the region," said Victor. "The whole of the infrastructure inside Syria has been basically decimated. And the impact on people has been absolutely massive. The reconstruction efforts required will be enormous, and I think we need to take that on board right now."
The violence continued Monday with Syrian fighters jets continuing to bomb the Damascus suburbs. Activists say air strikes on the rebel-held town of Moadamiyeh, southwest of the capital, killed at least 13 people, including women and children.
The Syrian government has been waging an offensive to dislodge rebels from strategic areas around Damascus. Activists reported at least 130 deaths across the country Sunday.
Meanwhile, Russia urged the rebels to make counter-proposals to those made by Syrian President Bashar al-Assad in a recent speech to start a dialogue that could end the fighting.
Russian 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 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.