UN report says Syria has committed war crimes
Syrian rebels fighting to topple President Bashar al-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, the investigators said.
The report called for the UN Security Council to take "appropriate action" given the gravity of documented violations by all sides.
The Security Council can refer a case to the prosecutor of the International Criminal Court, a United Nations tribunal, but Russia and China are reluctant to condemn Syria.
"We have identified both parties as guilty of war crimes and of course a greater number and of bigger variety from the government side," Karen AbuZayd, a senior US investigator, told Reuters.
"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.
The independent investigators, led by Brazilian Paulo Pinheiro, conducted more than 1,000 interviews over the past year to produce their latest 102-page report for the UN Human Rights Council.
Many of the interviewees were Syrian refugees or defectors who have fled to neighbouring countries.
They found "reasonable grounds" to affirm that government forces and the allied shabbiha militia had committed crimes against humanity, war crimes and gross violations of international human rights and humanitarian law.
These included "unlawful killing, torture, arbitrary arrest and detention, sexual violence, indiscriminate attack, pillaging and destruction of property".
Meanwhile, an air raid killed 30 people in the rebel-held northern border town of Azaz today, a local doctor said.
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.
Seven Lebanese hostages being held in Azaz were also wounded, with four others still missing, a rebel commander said.
Mr Assad's forces have increasingly used helicopter gunships and warplanes against the lightly-armed insurgents. (...)