The Syrian Government's "widespread and systematic" attacks against its own people may amount to crimes against humanity and warrant an investigation by the International Criminal Court (ICC), the United Nations human rights office said in a report released Thursday.

The Report of the Fact-finding Mission on Syria was produced by the Office of the UN High Commissioner for Human Rights (OHCHR), in response to a request by the UN Human Rights Council.

The mission was tasked with investigating "all alleged violations of international human rights law and to establish the facts and circumstances of such violations and of the crimes perpetrated."

It found "a pattern of human rights violations that constitutes widespread or systematic attacks against the civilian population, which may amount to crimes against humanity," states the report, which covers events from 15 March to 15 July.

As many as 2,000 Syrians have been killed in the past five months since the start of the pro-democracy protests, which are part of a broader uprising across North Africa and the Middle East that has led to the toppling of long-standing regimes in Tunisia and Egypt and conflict in Libya.

As Syria did not provide OHCHR access to the country, the findings in the report are based primarily on the mission's analysis of first-hand information obtained through interviews conducted with victims and witnesses.

It also examined more than 50 videos and numerous photographs related to apparent human rights violations, as well as information compiled by non-governmental organizations (NGOs), the media and other information in the public domain.

The 13-member mission, headed by Deputy High Commissioner for Human Rights Kyung-wha Kang, gathered corroborative eyewitness statements with respect to numerous summary executions, including 353 named victims, and describes the disproportionate use of force by Syrian military and security forces.

"Reports from witnesses indicate that there was a widespread modus operandi to kill civilians by using: (a), forces on the ground; (b), snipers on rooftops; and (c), air power," states the report. "Consistent with an apparent shoot-to-kill policy, most of the victims' bullet wounds were located in the head, chest and general upper body area."

Interviews were conducted with a number of former soldiers who had deserted the army, the police and different branches of the security forces, who stated that they received clear orders to use live ammunition against protesters, "and those who did not shoot civilians were shot from behind by other security officers and Shabbiha [an Alawite civilian militia] units."

From the 180 witness accounts taken by the mission, 98 revealed acts of torture and other examples of inhuman and degrading treatment of civilians by military and security forces. "A clear widespread or systematic policy appears to have been in place whereby security forces targeted people suspected of having taken part in demonstrations, with a view to intimidating and terrorizing them as a way of quelling protests."

The report adds that "children have not only been targeted by security forces, but they have been repeatedly subject to the same human rights and criminal violations as adults, including torture, with no consideration for their vulnerable status.

"The fact that Syrian forces have tortured or killed children on several occasions, in what are clearly not isolated incidents, causes grave concern," it states.

Bearing in mind the findings of the mission, High Commissioner for Human Rights Navi Pillay recalled the principle agreed in 2005 by all UN Member States, by which each State has the responsibility to protect its populations from crimes against humanity and other international crimes.

"When a State is manifestlyfailing to protect its population from serious international crimes, the international community has the responsibility to step in by taking protective action in a collective, timely and decisive manner," states the report.

The High Commissioner recommends that Syria immediately put an end to the gross human rights violations, as well as allow immediate access for humanitarian workers to assist those in need and for OHCHR to conduct investigations into all abuses.

Secretary-General Ban Ki-moon made the same appeal in a phone conversation yesterday with President Bashar al-Assad, during which the UN chief expressed appreciation that the Government had agreed to receive a UN humanitarian assessment mission and was assured that it would have access to different sites in the country.

Among her other recommendations, Ms. Pillay says the Human Rights Council should urge the Security Council to call for an immediate cessation of attacks against the civilian population, and to consider referring the situation in Syria to the ICC.

The High Commissioner will brief the Security Council later today on the situation in Syria, along with the Under-Secretary-General for Humanitarian Affairs, Valerie Amos.

In addition, the Human Rights Council will hold a second special session on the situation of human rights in Syria on Monday.