The death toll from the war in Syria has topped 191,000, UN rights chief Navi Pillay said on Friday, criticising "international paralysis" on the conflict where jihadists have established a foothold.
Pillay said the 191,369 deaths recorded between March 2011 when the war broke out and April this year, was nearly double that given a year ago, and was likely an underestimate.
Among the dead were 9,000 children, she said, with her spokesman stressing that up to 6,000 people were dying in Syria every month.
Pillay's comments came as a monitoring group reported that at least 70 Islamic State jihadist fighters had been killed in 48 hours of clashes with Syrian army troops in the northern province of Raqa.
IS military gains in Raqa and Aleppo provinces have prompted the Syrian government for the first time to launch intensive air strikes against the jihadists who have seized large swathes of territory straddling Syria and Iraq.
Pillay, who on Thursday chided the UN Security Council for what she called a lack of resolve in ending crises, said in a statement the dwindling global interest in Syria was "scandalous".
"I deeply regret that, given the onset of so many other armed conflicts in this period of global destabilisation, the fighting in Syria and its dreadful impact on millions of civilians has dropped off the international radar," she said.
"The killers, destroyers and torturers in Syria have been empowered and emboldened by the international paralysis," added the outgoing head of the UN high commissioner for human rights.
Jihadists of the Islamic State control large swathes of territory in northern and eastern Syria, where they sow terror and carry out executions like the beheading of US journalist James Foley.
The conflict erupted when security forces cracked down on protesters, sparking an uprising against President Bashar al-Assad's regime that escalated into full blown civil war.
Pillay said there had been "serious allegations that war crimes and crimes against humanity have been committed time and time again with total impunity" and complained that the deadlocked Security Council had failed to refer the case of Syria to the International Criminal Court "where it clearly belongs."
The United Nations last gave a death toll on the conflict in July 2013 when Secretary General Ban Ki-moon put the number killed at more than 100,000.
It had stopped providing tolls because of concerns over the accuracy of the numbers supplied by a range of sources, Pillay's spokesman Rupert Colville told reporters.
But after working closely with several of the groups, the rights agency again felt it was safe to report the numbers, he said, adding that between 5,000 and 6,000 people were dying in Syria every month.
Nearly 9,000 children, including more than 2,000 under the age of 10, were among the dead, it added, but cautioned that victims' ages had not been recorded in over 80 percent of cases.
The report did not apportion blame for the killings.
'70 jihadists killed'
On Friday, the Syrian Observatory for Human Rights said IS had launched a major push late Tuesday on Tabqa military airport, the last remaining army stronghold in Raqa, which has been largely overrun by the jihadists.
The assailants had carried out car bomb attacks in their assault but failed to make any breakthrough, the Britain-based group said.
At least 70 IS jihadists were killed early Wednesday in regime air raids, Scud missile blasts and explosions, said the head of the Observatory Rami Abdel Rahman.
He said the military was also using barrel bombs to attack IS from the air, the same improvised and crude weaponry it has deployed against rebel-held areas of the northern city of Aleppo with deadly impact.
Rebel groups have in the past accused the Damascus regime of avoiding attacks on IS as the Sunni extremist group battles more moderate anti-regime forces. IS initially worked alongside other rebel groups in Syria, but they turned against it because of its abuses and its bid to dominate seized territory.