At least 14 doctors and patients were killed after a direct airstrike destroyed a hospital specializing in pediatrics in Syria. Two of the eight doctors working at the Al Quds hospital in a rebel-held area of Aleppo were killed in Wednesday night's attack, according to Doctors Without Borders
Above: Civil defense members carry a casualty after an airstrike at a field hospital in the rebel-held area of al-Sukari in Aleppo, Syria on April 27, 2016.
The United Nations called on Moscow and Washington to salvage a "barely-alive" cease-fire. The city of Aleppo is at the epicenter of a military escalation that has undermined peace talks in Geneva to end the five-year-old war and U.N. envoy Staffan de Mistura appealed to the presidents of the United States and Russia to intervene and to salvage a "barely-alive" cease-fire.
Above: People walk through the rubble of destroyed buildings following a reported air strike on the rebel-held neighborhood of al-Kalasa in Aleppo on April 28.
A Syrian military source told Reuters that government warplanes had not been used in areas where airstrikes were reported.
Above: Syrian civil defense volunteers and rescuers remove a baby from under the rubble of a destroyed building in Aleppo on April 28.
People inspect the damage at a site hit by airstrikes in the rebel-held area of Bustan al-Qas, Aleppo on April 28.
Syrian men carry an injured youth in the government-controlled side of the northern city of Aleppo following fighting between regime forces and rebels on April 28.
Nearly 200 people have been killed in Aleppo in the past week as rebels have pounded government-held neighborhoods with rocket and artillery fire and the regime has hit rebel areas with air raids.
People inspect the damage at al-Quds hospital after it was hit by airstrikes in Aleppo, April 28.
The hospital featured an eight-bed pediatrics unit and was "the main referral center" for ailing children, Doctors Without Borders said. The facility employed eight doctors and 28 nurses. Following the airstrike there was little left of the emergency room, intensive care unit, and operating room, according to the organization. Doctors Without Borders initially said three of the doctors had been killed but later revised that figure to two.
The British-based Observatory said 31 people were killed as a result of air strikes on several areas of opposition-held Aleppo on Thursday. In addition, it said at least 27 people were killed in the air strike on the hospital that was struck.
Above: A man follows rescuers carrying the body of a boy on a stretcher in Aleppo, on April 28.
A man gestures as he stands on a damaged building at a site hit by airstrikes in Aleppo on April 28.
Aleppo is the country's second largest city, with a population of some 3.5 million, according to the CIA's World Factbook. It has been one of the war's worst affected metropolitan areas, with many neighborhoods suffering heavy damage and swathes of its population without water and power for months.
A Syrian boy is comforted as he cries next to the body of a relative who died in a reported airstrike on April 27 in Aleppo.
Above: A front loader operates at a site hit by airstrikes in Aleppo on April 28.
The Geneva talks aim to end a war that has killed more than 250,000 people, created the world's worst refugee crisis, allowed for the rise of Islamic State and drawn in regional and major powers but the negotiations have all but failed and a truce to allow them to take place has collapsed.