“Gross violations of human rights have grown in number, in pace and in scale,” Paulo Sergio Pinheiro told diplomats gathered in Geneva, as more violence shook Damascus and Syria’s second city Aleppo.

Pinheiro, head of a UN commission tasked with probing the abuses, said violations were occurring with such frequency that it was becoming impossible to investigate them all.

“Civilians, many of them children, are bearing the brunt of the spiralling violence,” he told the United Nations Human Rights Council.

Pinheiro described “a dramatic escalation, indiscriminate attacks on civilians in the form of air strikes and artillery shelling levelled against residential neighbourhoods,” decrying “a disturbing disregard for established rules of armed conflict.”

“The human rights situation in the Syrian Arab Republic has deteriorated to such a degree that it is difficult to describe,” he said.

Pinheiro was presenting an updated version of his commission’s report from last month, which said Syrian President Bashar al-Assad’s regime, and the opposition to a lesser extent, had committed war crimes during the 18-month crisis.

UN High Commissioner for Human Rights Navi Pillay drew a similarly depressing picture Monday, pointing to increasing reports of atrocities carried out by both sides in the conflict, as well as the use of child soldiers by opposition forces.

Pinheiro said his commission had “recommended that our report be forwarded to the Security Council for its deliberations so it might take appropriate action in view of the gravity of the violations, abuses and crimes perpetrated by government forces and the Shabbiha (allied militia), and by anti-government groups.”

The UN commission had drawn up a second confidential list of “individuals and units believed to be responsible for human rights violations,” Pinheiro told reporters Monday, hinting it wanted to see the cases referred to the International Criminal Court.

He stressed though that it would be up to the deeply divided UN Security Council to decide whether to ask the ICC to get involved.

In their comments after his presentation, representatives of a number of countries also called for the perpetrators of atrocities Syria to be sent to the ICC, as did Human Rights Watch.

But Faysal Khabbaz Hamouia, a representative of the Syrian government, slammed the report as inaccurate and biased.

He also charged that the international community was stoking the flames of the conflict, while 17 countries were sending “jihadist terrorists” to fight for the “fragmentation of the Middle East into Islamic emirates.

Pinheiro agreed that a growing number of “foreign elements” including militant jihadists had entered Syria — some working with anti-government forces and some working alone — and that they did not only come from Syria’s closest neighbours.

“They have their own agenda. This is more worrisome,” he told reporters.

If the Human Rights Council calls for the Security Council to ask the ICC to get involved, it would be a first step towards eventually bringing those responsible for atrocities in Syria to justice.

However, the next step — consensus in the Security Council on the matter, which could be part of a resolution to be voted on next week — is easier said than done.

A year and a half into the crisis, the international community remains paralysed, with the West, the Gulf Arab countries and Turkey calling for the removal of Assad, and Russia and China standing by him.

But Pinheiro cautioned perpetrators of atrocities in the country against thinking they could act with impunity.

“We have collected an extraordinary body of evidence,” he said.

But Pinheiro stressed that his commission would not make its list of suspected war criminals public, citing the commission’s lower standard of proof as compared to a court of law.

Since the commission was created a year ago, it has held more than 1,100 interviews with perpetrators and victims in the conflict, but has not been able to actually visit Syria — a fact that Pinheiro lamented Monday.

He called for the commission’s mandate, which in principle ends next week, to be renewed.

Overall, the death toll from the conflict has risen to more than 27,000, according to the Syrian Observatory for Human Rights, which relies on activist accounts from the ground. The United Nations puts the toll at 20,000.