The UN rights council on Friday called for a special investigation into violence in Aleppo in a resolution fiercely critical of Syria's government.
The text spearheaded by Britain repeatedly condemned Syrian President Bashar al-Assad's offensive to retake east Aleppo from rebel forces, while also admonishing "terrorist acts" by the Islamic State group and other extremists in the Syrian conflict.
Russia, an ally in Syria's east Aleppo campaign, condemned the resolution which was approved in a majority vote.
Moscow's envoy to the council, Aleksei Goltiaev, also described criticism of Syria and Russia as "pathetic".
The resolution called for the UN's existing Commission of Inquiry for Syria (COI) to "conduct a comprehensive, independent special inquiry into the events in Aleppo", and to identify individuals responsible for the most serious violations.
Assad's government has repeatedly denied COI investigators access to the country, although they have published multiple reports documenting violations.
The resolution demanded that warring parties "in particular the Syrian authorities and their allies", allow unrestricted humanitarian access to desperate civilians and "end immediately all bombardments and military flights over Aleppo city".
It also condemned "the starvation of civilians as a means of combat". East Aleppo, captured by the rebels in 2012, has not received aid since July 7 when regime forces seized the last supply route.
John Fisher of Human Rights Watch said the resolution passed at a special session on Aleppo "sent a clear message that illegal attacks on civilians must end and that those responsible will be held to account".
UN rights chief Zeid Ra'ad Al Hussein opened the debate by denouncing "crimes of historic proportions" being perpetrated in east Aleppo, where an estimated 250,000 people have been besieged under the joint offensive by Damascus and Moscow.
A so-called "humanitarian pause", initiated by Russia, has been broadly holding since Thursday in east Aleppo but the UN and Red Cross have not yet gained access to the rebel side of the city.
The UN had voiced hope it could begin medical evacuations on Friday before bringing in dozens of aid-filled trucks, but said the security guarantees needed to mobilise had not yet been provided.