AZAZ — A Syrian air raid killed 30 people in the rebel-held northern border town of Azaz Wednesday, a local doctor said, and a bomb went off near UN and military sites in the capital Damascus, wounding three.



The doctor, Mohammad Lakhini, said at a hospital in Azaz that scores of people were wounded in the air strike. It reduced several houses in the town to rubble and dozens of men clawed through the concrete and metal debris looking for survivors.



As the violence intensified, UN human rights investigators accused forces loyal to Syrian President Bashar Al-Assad of committing war crimes and crimes against humanity.



They said rebels had also committed war crimes, but the violations “did not reach the gravity, frequency and scale” of those by state forces and the pro-Assad shabbiha militia.



“The commission found reasonable grounds to believe that government forces and the shabbiha had committed the crimes against humanity of murder and of torture, war crimes and gross violations of international human rights law and international humanitarian law, including unlawful killing, torture, arbitrary arrest and detention, sexual violence, indiscriminate attack, pillaging and destruction of property,” said the 102-page report by the independent investigators led by Paulo Pinheiro.



In video posted by activists earlier in the day, residents in Azaz — situated just north of the major urban battleground of Aleppo — screamed and shouted “God is Greatest” as they carried bloodied bodies from collapsed concrete buildings.



The opposition Syrian Observatory for Human Rights said dozens had been killed. One activist in the town said at least 30 bodies had been found and rescuers were searching for more.



The video footage, which could not be immediately verified, showed crowds of residents wrestling with steel bars and pulling away a giant slab of concrete to reveal the dust-covered arm of a child. “This is a real catastrophe,” said an activist who gave his name only as Anwar. “An entire street was destroyed.”



Assad’s forces have increasingly used helicopter gunships and warplanes against the lightly-armed insurgents.



In Damascus, a bomb exploded in the car park of a hotel used by UN monitors, but several military buildings are also in the vicinity and it was not clear what the target was.



No UN staff were hurt in the blast, which occurred exactly four weeks after a bomb killed four of Assad’s senior aides. The bomb set a fuel tanker ablaze and black smoke billowed over the city. Ash and dust covered white UN vehicles parked nearby. — Agencies