In its latest report released Monday, the United Nations Commission of Inquiry on Syria noted that the scale of violations committed by government forces and affiliated militia "significantly" exceeded those of armed opposition groups.

Although the government has yet to allow the commission to undertake investigations inside Syria, the 445 interviews conducted in this reporting period exposed the human cost of a progressively radicalized and militarized conflict.

Large parts of Syria are witnessing continuous combat, involving more brutal tactics and new military capabilities on all sides. The war has taken on sectarian overtones, permeated by opportunistic criminality, and aggravated by the presence of foreign fighters and extremist groups.

According to the report, a humanitarian disaster has resulted in Syria, with tens of thousands killed and millions internally displaced. Over 820,000 Syrians have sought refuge in neighboring countries.

Government forces and armed opposition groups have perpetrated massacres of civilians and hors de combat fighters. Across Syria, during house searches and at checkpoints, government forces and affiliated militias "have arbitrarily arrested individuals," said the report.

At these locations -- and in official and unofficial detention centres -- murder, torture, rape, enforced disappearance and other inhumane acts have taken place. Committed as part of a widespread and systematic attack, they may constitute crimes against humanity, said the report.

As anti-government groups gained control over territory, the commission found that they committed murder, torture, arbitrary arrests and hostage-taking, all of which may constitute war crimes. Car and suicide bombings, directed at non-military targets, by armed groups spread terror among the civilian population.

Anti-government groups continue to conduct their operations from within densely populated towns and villages, endangering remaining civilians. The number of foreign fighters has grown, though they remain a small proportion of the armed groups' ranks.

Both sides have violated the rights of children. Incidents of children being killed, tortured and raped by pro-government forces were recorded. Children under the age of 15 have actively participated -- including as fighters -- in hostilities as part of some anti-government armed groups.

In March, a confidential list of individuals and units believed to be responsible for crimes will be submitted to the United Nations High Commissioner for Human Rights.

Syrian Prime Minister Wael al-Halqi has called on all components of the Syrian people to engage in a political process on the Syrian soil to end the country's long-standing crisis in accordance to the political vision outlined recently by President Bashar al-Assad. Endi