Smoke and dirt rise from the city of Severodonetsk in the eastern Ukrainian region of Donbas on June 17, 2022, as the Russian-Ukraine war enters its 114th day. AFP
"The city has been fully occupied by the Russians," mayor Oleksandr Striuk said.
The Ukrainian army on Friday said it would withdraw its forces from the city of some 100,000 inhabitants before the war to better defend the neighbouring city of Lysychansk.
Striuk said civilians had started to evacuate the Azot chemical plant, where several hundred people had been hiding from Russian shelling.
"These people have spent almost three months of their lives in basements, shelters. That's tough emotionally and physically," he said, adding they would now need medical and psychological support.
Pro-Moscow separatists said Russian and pro-Russian forces had taken control of the Azot factory and "evacuated" more than 800 civilians sheltering there.
The forces have "taken full control of the Azot plant industrial zone", a separatist representative Andrei Marochko said on Telegram.
Another separatist spokesman, Ivan Filiponenko, said that around 800 civilians who had taken refuge in the plant during weeks of fighting had been "evacuated".
The Russians also taking control of Lysychansk would effectively give the them control of the wider Lugansk region, and allow them to push further into the wider Donbas.