The humanitarian situation in eastern Ukraine is getting worse, as violence intensifies, supplies dwindle, and more than a thousand people flee their homes every day, a UN official said Tuesday.

At an emergency Security Council meeting called by Russia on Tuesday, director of UN humanitarian operations John Ging called for "immediate action" to quell the violence and devastation. He noted that drinking water, food, and power supplies have sustained serious damage, an estimated 70 percent of health workers have fled, and hundreds of houses and buildings have been destroyed.

#Donetsk got hit hard again. Attack in ul. Tekstilchiki 9. School hit + direct hit on market at crossroad #Ukraine pic.twitter.com/crhLafBqIB — Mark Bartalmai (@MarkBartalmai) August 6, 2014

According to the Associated Press, Russia's U.N. Ambassador Vitaly Churkin said the situation in the east, particularly in Luhansk and Donetsk, is "disastrous." He accused the Ukrainian military of indiscriminate shelling of housing and said Russia wants to send a humanitarian convoy to Luhansk and Donetsk under the auspices of the International Committee of the Red Cross.

Even as the Ukrainian army encircled the separatist-held cities, authorities denied there was a humanitarian crisis in Ukraine.

The UN was critical of Ukraine's response to the crisis, with Vincent Cochetel, the Director for the European Bureau at the UN Refugee Agency, noting that “the current lack of a systematic and uniform system hampers the coordination and implementation of relief efforts. This is also important as the Ukrainian authorities make their preparations for winter. Most of the current shelters in use are not suitable for the cold winter months.”

Heavy fighting—including air strikes and rocket fire—hit the region Tuesday and continued on Wednesday, amidst reports of Russian troops massing on Ukraine's eastern border.

For the first time, shelling hit the city center of rebel-held Donetsk overnight, reportedly killing three people. Civilians and separatists blamed Ukrainian forces for the attack. Kiev denied the accusations.

The Wall Street Journal described the scene:

"But they told us they wouldn't bomb Donetsk, they told us!" one woman said, in reference to Kiev's pledge to avoid using heavy weaponry in residential areas. "It's a total nightmare," said another neighbor as she emerged from the mangled entryway to the apartment blocks. Many of its windows had been shattered in the blast. The whistling of shells around noon local time pierced the summer silence that has descended on the city, which tens of thousands of people have fled in recent weeks. There was no immediate confirmation of who had fired the shells, but neighbors and rebels blamed Ukrainian forces, speculating that their intended target was the separatist compound right next door.

Last week, the Office of United Nations High Commissioner for Human Rights said "a total breakdown of law and order and a reign of fear and terror have been inflicted by armed groups on the population of eastern Ukraine." Just over 4,000 people have been wounded in eastern Ukraine since April, and more than 1,300 have been killed.