The United Nations has raised the alarm over the threat of a possible chemical disaster due to the armed conflict in eastern Ukraine.

A UN human rights expert said in a statement issued on March 10 that fighting has been under way in areas where large chemical and industrial facilities are located.

"Battles are now being fought in cities, close to industrial centers, with factories increasingly becoming at risk of being hit: the consequences for anyone living close-by would be severe," said Baskut Tuncak, the UN Special Rapporteur on human rights and hazardous substances and wastes.

Tuncak said that a storage building containing more than 7,000 kilograms of chlorine gas was hit by shelling on February 24.

No storage container was damaged in the shelling, Tuncak said. But he warned that if one single 900-kilogram container had been broken, it could have killed everyone within a 200-meter radius and could have resulted in severe health damage for those living as far as 2.4 kilometers around the damaged facility.

"In case of extensive damage, people living within 7.4 kilometers downwind of the facility would need to be moved away within 24 hours," the statement said.

The UN statement did not specify the location or the name of the chlorine storage facility.

But in a statement on February 25, the monitoring mission for the Organization for Security and Cooperation in Europe (OSCE) reported having noticed damage caused by shelling at the Donetsk Water Filtration Station, in an area controlled by Russia-backed separatists.

The OSCE statement said a drone in the area had established the damage was caused by 82 mm mortar rounds, but did not say who had fired them.

Most of Ukraine’s industrial facilities are located in the eastern part of the country, where fighting between government forces and Russia-backed separatists has killed more than 9,750 people since April 2014.