Russian-backed separatists from the self-proclaimed Luhansk People's Republic said Ukraine has disrupted a humanitarian corridor from the Azot chemical plant in Sievierodonetsk, RIA news agency reported on Wednesday.

Serhiy Haidai, governor of Luhansk region, has said that around 500 civilians are sheltering in the plant, which has become the final stronghold of Ukrainian troops in the Donbas region city, where fighting has raged for weeks.

Russian forces had said that civilians would be free to depart the Azot plant throughout Wednesday. (Reporting by Reuters; editing by Guy Faulconbridge)