MOSCOW (Reuters) - Russia said on Tuesday that a Syrian army breakthrough in Aleppo had dramatically altered the situation on the ground, allowing more than 80,000 civilians to obtain humanitarian aid after years of being used as “human shields” by rebels.

Moscow is helping forces loyal to President Bashar al-Assad try to take back full control of the shattered city by providing training, equipment, advice and intermittent air support.

On Monday, the Syrian army and its allies announced the capture of a large swathe of eastern Aleppo from rebels in an accelerating attack that threatens to crush the opposition in its most important urban stronghold.

“During the last 24 hours, thanks to very well prepared and careful actions, Syrian soldiers were able to radically change the situation,” Major-General Igor Konashenkov, a spokesman for the Russian defense ministry, said in a statement.

“Practically half of the territory occupied by rebels in recent years in the eastern part of Aleppo has been completely liberated.”

The advance has stirred concern in the West about the fate of Aleppo’s entrapped civilian population.

France called for a United Nations Security Council meeting to try to end hostilities there, and politicians and officials in Britain, Germany and the United States have all spoken of their worry that civilians are being killed.

Konashenkov called allegations of large civilian losses during the Syrian government operation alarmist and said Moscow was shocked by what he called the West’s “blindness” when it came to assessing the real situation on the ground.

More than 80,000 civilians, including tens of thousands of children, had been able to access Russian humanitarian aid in the form of water, food and medical aid as a result of the military breakthrough, he said.

“These Syrians were used as human shields for long years in Aleppo by terrorists of all allegiances,” said Konashenkov.

President Vladimir Putin ordered the defense ministry and the emergency situations ministry to urgently dispatch mobile field hospitals to Aleppo to help wounded civilians.

Russia’s ceasefire monitoring center said 507 rebels had laid down their arms in recent days. It said 484 rebels who were local residents had immediately been pardoned in line with an earlier order by Assad.