Syria crisis: Brahimi warns horror is 'unprecedented'
The conflict in Syria has reached "unprecedented levels of horror", peace envoy Lakhdar Brahimi has told the UN Security Council.
The UN-Arab League envoy said Syria was being destroyed "bit by bit" with grave consequences for the wider region.
He was speaking hours after evidence emerged of a fresh massacre in the northern city of Aleppo.
At least 71 bodies were found by a river in the western Bustan al-Qasr district, opposition activists said.
Most had their hands tied behind their backs and gunshot wounds to the head.
Mr Brahimi has been trying to find a solution to the crisis based on a peace plan approved at an international conference in June 2012.
The UN says the conflict has left more than 60,000 people dead.
The BBC's Barbara Plett at the UN says Mr Brahimi delivered a blunt assessment of the situation in Syria that reflected his frustration with the deadlock in the Security Council.
"Unprecedented levels of horror have been reached. The tragedy does not have an end," Mr Brahimi told a closed meeting of the 15-member council, according to diplomats.
"The country is breaking up before everyone's eyes. Only the international community can help, and first and foremost the Security Council."
Speaking later to reporters, Mr Brahimi said the Syrian government and the opposition were, between them, destroying Syria "bit by bit".
"The region is being pushed into a situation that is extremely bad," he said.
"That is why I believe the Security Council simply cannot continue to say: 'We are in disagreement, therefore let's wait for better times.' I think they have to grapple with this problem now."
The UN Security Council has been divided over Syria for months.
The US, UK, France and other Western powers have pushed for resolutions that threaten sanctions against President Bashar al-Assad's government.
However, Russia and China have vetoed such resolutions three times. Moscow - a close ally of Syria - also refuses to back calls for Mr Assad to step down.
Earlier, video footage of the gruesome discovery in Aleppo was posted by activists on YouTube.
It showed a large number of bodies strewn in and around the banks of the Quwaiq river, which skirts the western side of Aleppo.
The bodies were caked in mud and showed signs of rigor mortis. There were also signs of blood having poured from many of the heads.
The government and opposition have blamed each other for the killings.
The district of Bustan al-Qasr has been hotly contested since fighting broke out in Aleppo last July, correspondents say.