The UN Security Council has unanimously approved a 30-day ceasefire in Syria to allow for humanitarian aid deliveries and medical evacuations in war-ravaged areas.

The vote came as bombs continued to be dropped on Eastern Ghouta, the rebel-held suburb outside the capital of Damascus. More than 520 people have been killed and 2,500 have been wounded in the fighting in the last week, according to Médecins Sans Frontières.

The UN Secretary General António Guterres had called for a ceasefire earlier this week, warning that “a human tragedy is unfolding in front of our eyes [with] 400,000 people living in hell on earth".

The Security Council resolution calls for the fighting to stop "without delay" so that emergency aid supplies can be delivered and the injured evacuated. The vote was delayed by several days, as delegates said Russia – an ally of Syrian President Bashar al-Assad's – refused to a agree to a proposal.

Russian ambassador Vassily Nebenzia had called the motion “unrealistic” and accused other council members of being misled by a “massive psychosis”. The country – which provides military support to Mr Assad's forces – agreed to the resolution on Saturday, after a requirement that the ceasefire be implemented in 72 hours was dropped.

Eastern Ghouta bombings: Syrian war in pictures Show all 14 1 /14 Eastern Ghouta bombings: Syrian war in pictures Eastern Ghouta bombings: Syrian war in pictures A Syrian woman and children run for cover amid the rubble of buildings. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures Smoke rises from buildings following the attack on the village of Mesraba in the rebel-held besieged Eastern Ghouta region on the outskirts of the capital Damascu. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures Injured children receive medical treatment. EPA Eastern Ghouta bombings: Syrian war in pictures A Syrian man carries a child injured. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures An injured child receives treatment following bombings on several areas of eastern Ghouta. EPA Eastern Ghouta bombings: Syrian war in pictures A child reacts inside a hospital after relatives were injured in the bombing. EPA Eastern Ghouta bombings: Syrian war in pictures Syrian children cry at a make-shift hospital in Douma following air strikes on the Syrian village of Mesraba. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures Syrian Civil Defense group extinguishing a store during airstrikes and shelling by Syrian government forces. AP Eastern Ghouta bombings: Syrian war in pictures A wounded 12-year-old Syrian boy, cries as he receives treatment at a make-shift hospital. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures Syrians carry a wounded man. AFP/Getty Eastern Ghouta bombings: Syrian war in pictures An injured man covered with blood at a medical point. Reuters Eastern Ghouta bombings: Syrian war in pictures People sit a medical point in the besieged town of Douma, Eastern Ghouta. Reuters Eastern Ghouta bombings: Syrian war in pictures Syrian Civil Defense running to help survivors. AP Eastern Ghouta bombings: Syrian war in pictures Injured children receive medical treatment. EPA

US Ambassador to the UN Nikki Haley criticised Russia for "stalling" the vote on Friday. In a speech after Saturday's vote, she said the council as "very late" in taking action.

"In the three days it took us to adopt this resolution, how many mothers lost their kids to the bombing?" she asked.

The bombings in Eastern Ghouta this week have overwhelmed hospitals and left residents with little food or medical supplies. More than 22 medical facilities have been damaged in some of the worst violence seen since the start of the civil war seven years ago, according to Syrian activists.

Scenes of devastation in Syria after deadly shelling and airstrikes and eastern Ghouta

The country's civil defence rescue service, known as the White Helmets, said it was difficult to get an accurate count of the number of dead and injured because of the relentless bombardment.

“Maybe there are many more,” Siraj Mahmoud, a spokesman for the group told Reuters. “We weren’t able to count the martyrs yesterday or the day before because the warplanes are touring the skies.”

An estimated 400,000 people live in Eastern Ghouta. The government claims they are firing on al-Qaeda-linked groups in the area and only targeting militants.