Airstrike in April left rebel-held Aleppo neighborhood of al-Kalasa in rubble
Airstrike in April left rebel-held Aleppo neighborhood of al-Kalasa in rubble
(CNN) —  

A 48-hour “extendable ceasefire” has been secured for the war-ravaged Syrian city of Aleppo, the United States and Russia said.

Brett McGurk told CNN’s Christiane Amanpour on Wednesday the cease-fire was expected to start Thursday. He stressed that the parties need to do all they can to enforce a “cessation of hostilities.”

“We’re going to take the next few days to try to get something in place, particularly in the northern section of Aleppo, where the cessation of hostilities is completely fraying,” said McGurk, the U.S. envoy for the anti-ISIS coalition.

The Russian Defense Ministry said a 48-hour “regime of silence” will be enforced in Aleppo.

The initiative is designed “to reduce the level of armed violence and stabilize the situation,” the ministry said in a daily bulletin posted on its website.

The United States and Russia have been working to enforce ceasefires in the city and surrounding region.

Daily warfare

The Syrian Observatory for Human Rights, a watchdog group, reported casualties Wednesday from heavy shelling on areas controlled by regime forces in Aleppo.

It reported fighting between the Islamic State and rebels in the northern countryside and it cited fighting between regime forces and allied militia and rebel and Islamic factions and the al-Nusra Front.

Last week, the U.N. humanitarian wing decried the latest escalation of violence in Aleppo, where dozens of casualties have been reported in attacks on two medical facilities.

Since April, attacks in Aleppo and the surrounding areas have resulted in hundreds killed or injured, the Office for the Coordination of Humanitarian Affairs said.

“It has also caused damage to schools, hospitals and other civilian infrastructure, and hindered humanitarian aid operations,” U.N. spokesman Stéphane Dujarric told journalists in New York. He said that such attacks “can constitute violations of international humanitarian law.”

“We call on all parties to the conflict to take all measures to protect civilians and facilitate humanitarian access, as required under international humanitarian law, in order to safeguard the lives of all civilians,” Dujarric said.

“Just truly unconscionable’

The U.N. agency that handles the affairs of Palestinian refugees in the Middle East denounced the deadly violence, saying Palestinians in the region have been caught in the crossfire.

McGurk decried the situation.

“There’s really two main battles going on in Aleppo. So we’ve been very analytically precise about this that, under the cessation of hostilities, the Nusra Front, Al Qaeda’s affiliate, is not a protected party. So the regime has every right to defend against that offensive.

“They have absolutely no right, however, to continue this offensive in the northwest part of the country, in which they’re trying to cut off the opposition supply lines into the city. So that has to stop. There’s ongoing discussions about this actually right now, about settling down the situation. It’s just truly unconscionable.