(London) – Syrian government forces and militia fighters are obligated to provide civilians safe passage out of al-Qusayr and surrounding towns. Thousands of civilians have left al-Qusayr since a government offensive began in April 2013. Local opposition activists told Human Rights Watch that recent government attacks on fleeing civilians, including a reported attack on May 31, have made it difficult to escape and put remaining civilians, including many wounded, at great risk.

Human Rights Watch expressed grave concern for the safety of the remaining civilian population as well as wounded and captured fighters on all sides. Concerned governments should press Syrian authorities to abide by their obligations under international humanitarian law, including not targeting civilians, allowing humanitarian agencies immediate access, and treating humanely all persons in custody.

“Any forces that block civilians from leaving al-Qusayr are committing serious violations of the laws of war,” said Sarah Leah Whitson, Middle East director at Human Rights Watch. “Syrian government forces must not target civilians and need to allow relief aid to get to the population at risk.”

In earlier fighting in Syria, such as the government’s operations in Daraya and Moadamiya in August 2012, Human Rights Watch documented retaliatory attacks against civilians, including executions, after opposition fighters withdrew.

Opposition activists from al-Qusayr told Human Rights Watch that approximately 8,000 civilians and another 1,200 wounded were in need of urgent assistance in al-Qusayr and nearby Eastern Buwayda and Dab`a amid intense shelling. These numbers cannot be confirmed as no independent nongovernment organizations currently have access to the area. Human Rights Watch urged the Syrian government to grant humanitarian agencies immediate access to treat the wounded and evacuate civilians.

On May 31, a convoy of civilians seeking to flee al-Qusayr was attacked by alleged Syrian government forces, according to a pro-opposition activist who made statements to the media. Local opposition activists also told Human Rights Watch that, due to attacks by encircling government forces, escape routes for civilians have become unsafe.

Multiple media accounts reported that on May 10 the Syrian army had dropped leaflets over al-Qusayr calling on civilians to leave the city, with a map of a safe route by which to evacuate. The Syrian Arab Red Crescent met some of the fleeing residents to assist with their evacuation. On May 31, in statements to the media, a spokesman from the United Nations High Commissioner for Refugees (UNHCR), said more than 3,500 people, mostly women and children, had managed to escape from al-Qusayr to a nearby town. A visiting emergency team found they were living in dire conditions and suffering from health problems as a result. Several thousand residents from al-Qusayr are also reported to have fled to Lebanon and registered with UNHCR there.

On May 30, the United Nations Human Rights Council passed a resolution that called on the Syrian government to “allow free and unimpeded access by the United Nations and humanitarian agencies to all civilians affected by the violence, especially in Al Qusayr, through all effective routes, including by providing authorization for cross-border humanitarian operations as an urgent priority.”

Under international humanitarian law, warring parties must allow and facilitate rapid and unimpeded passage of humanitarian relief for civilians in need. Denying civilians access to food and medical care is a serious violation of international humanitarian law, and intentionally attacking personnel, installations, material, units, or vehicles involved in relief efforts is a war crime.

The UN Security Council should urgently refer the situation in Syria to the International Criminal Court, the body most capable of addressing serious violations by all parties in Syria, Human Rights Watch said. This would send a clear message that those responsible for attacks against civilians or captured combatants will be held to account. Concerned governments and inter-governmental bodies should urgently support this call to the Security Council.

“Before the next massacre takes place, governments should urge the Security Council to refer Syria to the International Criminal Court,” Whitson said. “This should make it clear that those responsible for war crimes in Syria will be brought to justice, and head off future atrocities.”