Fresh air strikes on Eastern Ghouta in Syria have brought the death toll from today's bombardment on the rebel-held enclave to 45, according to a monitoring group.

The Syrian Observatory for Human Rights said that at least 18 of the victims were killed in strikes carried out by Russian warplanes on the town of Hammuriyeh.

The group said four of the 45 people who died were children.

The raids bring to around 850 the number of civilians killed since Syrian and allied forces intensified their air campaign on the besieged enclave on 18 February.

The Syrian Observatory for HumanRights also said that pro-government forces have effectively cut Eastern Ghouta in half.

The onslaught has prompted outrage against the regime, with the United Nations' human rights chief Zeid Ra’ad al-Hussein accusing the government of orchestrating an "apocalypse" in Syria.

The Syrian Observatory for Human Rights said that pro-government forces had effectively cut Eastern Ghouta in half.

It said the forces had brought the strip of territory linking the north and south of the enclave within firing range, effectively bisecting the densely populated area on the outskirts of the Syrian capital Damascus.

The UN Security Council has called for a ceasefire to be implemented across Syria and expressed concern about the country's humanitarian situation, according to the Netherlands UN Ambassador Karel van Oosterom, council president for March.

"The cessation of hostilities was discussed. The Security Council reiterated its call for implementation of resolution 2401," he said.

The 15-member council unanimously demanded a 30-day truce across Syria on 24 February.

Mr van Oosterom was speaking after the Security Council was briefed behind closed doors on the situation in Syria at the request of the UK and France.