GENEVA - Syrian government forces and allied shabbiha militia have committed war crimes and crimes against humanity, including murder and torture in what appears to be state-directed policy, UN human rights investigators said on Wednesday.Syrian rebels fighting to topple Syrian President Bashar Assad have also committed war crimes but these "did not reach the gravity, frequency and scale" of those carried out by the army and security forces, they said.War plane strikes Syrian town, killing 80, doctor saysIn the latest violence in Syria, an air strike by a Syrian jet in the northern town of Azaz killed 30 people on Wednesday and wounded 150, a local doctor said.The doctor, who identified himself only by his first name Mohammad, was speaking at a hospital in Azaz. Activists had earlier said at least 30 people were killed.Residents screaming and shouting "God is greatest", carried bloodied bodies away from collapsed concrete buildings, video published by activists on YouTube showed.Syrian forces fighting the 17-month-old revolt against Assad have increasingly used helicopter gunships and fighter jets against the rebels, weaponry that the lightly armed opposition fighters cannot match."A fighter jet flew over the town and first it fired at a car, and blew it up. Then it started firing on a street nearby and several buildings collapsed, there was nothing we could do. I expect the death toll will climb as we keep digging through the rubble," the activist, who called himself Anwar, told Reuters.The activist video showed crowds of residents trying to untangle steel reinforcement bars and pull away a giant slab of concrete. The small arm of a child, covered in dust, could be seen beneath it. "This is a real catastrophe," Anwar said. "An entire street was destroyed."It was not immediately possible to independently verify the footage."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.Both government forces and armed insurgents had violated rights of children during the 17-month-old conflict, it said.Karen AbuZayd, an American expert serving as senior investigator alongside Pinheiro, told Reuters: "We have identified both parties as guilty of war crimes and of course a greater number and of bigger variety from the government side."What happened on the government side appears to be a policy of the state. It is not just widespread but similar large-scale complex operations, how they are carried out, the way the military and security work together," she said. Completing their inquiry into a massacre in Houla north of Homs in late May, the investigators said on Wednesday that government forces and Shabbiha fighters were responsible for the killings of more than 100 civilians, nearly half of them children.The investigators said they would update their confidential list of suspects or units responsible for violations and hand it over to UN rights boss Navi Pillay next month.