More than 1,000 people killed by 1,700 airstrikes on east Aleppo in just one week
The UN has announced a probe into the bombing of an aid convoy in Syria that killed at least 18 people last week.
Both Syria and Moscow deny involvement in the bombing, but Russia has released footage which it claims proves that weapons were being transported alongside the humanitarian aid.
In a statement, the UN said an internal board of inquiry will be established to investigate the strike on the Syrian Arab Red Crescent (SARC) trucks.
The board of inquiry will “ascertain the facts” and report back to Secretary-General Ban Ki-moon, who will then decide what further steps to take, it said.
The organisation previously warned that the attack in rebel-held Urm al Kubra, near Aleppo, could amount to a war crime if it was deliberate.
It came just hours after Syria's military declared an end to the week-long ceasefire brokered by the US and Russia.
All aid convoys to the country were suspended by the UN in the aftermath of the bombing, whose victims included the local SARC head, Omar Barakat.
Russia said this week that it will continue to back Syrian President Bashar al Assad and press on with its bombing campaign.
US President Barack Obama and German Chancellor Angela Merkel have condemned continued Russian and Syrian airstrikes as "barbarous".
But the Kremlin insisted on Thursday that it would "continue the operation of its air force in support of the anti-terrorist activity of Syria's armed forces".
US ambassador to the UN Samantha Power described the recent escalation as "the most savage week we've seen in an incredibly savage five-plus-year war", with more than 1,000 people killed by 1,700 airstrikes on east Aleppo alone.
Meanwhile, there are reports this morning that a hospital in Aleppo has been struck by two barrel bombs.
The blast is said to have hit a clinic in a rebel-held area of the besieged city, but it is not yet clear how many people have been injured.