GENEVA - The United Nations is calling for an end to the violence and relentless air attacks against eastern Aleppo, warning that the ancient Syrian city is being bombed into oblivion.

After a short pause, the Syrian government of Bashar al-Assad, backed by its Russian ally, unleashed its fire power one week ago against eastern Aleppo. It since has been mercilessly pounding the city’s hospitals, schools and other civilian infrastructure.

Spokesman for the U.N. Organization for the Coordination of Humanitarian Affairs Jens Laerke says the consequences for eastern Aleppo’s 275,000 civilians are devastating.

"It is absolutely heartbreaking and unacceptable that we all are witnessing what is happening almost on direct television, direct transmitted what may amount to war crimes in eastern Aleppo," said Laerke. "We need the political actors and the actors on the ground to create a situation whereby we can implement the U.N. plan."

That plan calls for a humanitarian pause to the fighting to allow U.N. aid convoys to deliver desperately needed food, medicine and other essential relief supplies to the trapped inhabitants of eastern Aleppo.

The plan also calls for the warring parties to allow the United Nations to evacuate wounded and sick people along with their family members so they can receive critical medical treatment.

Schoolchildren evacuate a school after shelling by Schoolchildren evacuate a school after shelling by Syrian rebels on government-held western Aleppo, Syria, in this handout picture provided by SANA on Nov. 20, 2016. Schoolchildren evacuate a school after shelling by Syrian rebels on government-held western Aleppo, Syria, in this handout picture provided by SANA on Nov. 20, 2016.

U.N. Human Rights Spokesman Rupert Colville calls the situation in eastern Aleppo ghastly. He says there is no doubt that war crimes are being committed by all sides in Syria.

"I have been doing this kind of work for 23, 24 years. With the possible exception of the Rwanda genocide, I cannot think of anything worse than Syria… You get people dying horrible deaths every day," said Colville. "You have got widespread torture. You have got massive detention. Thousands and thousands of people who have disappeared. Huge casualties. So huge, no one even knows how many there are anymore."

While the people of rebel-held eastern Aleppo are most victimized by this war, the United Nations says people in government-controlled western Aleppo also are suffering from indiscriminate shelling by opposition forces.

It says dozens of civilians in western Aleppo are dying every week and they, as well as the citizens in the eastern part of the city, are in need of protection.