Ukraine expects a new wave of attacks in the east and northeast, the head of Avdiivka's military administration has said.
Vitaliy Barabash said Russia was bringing in forces and equipment to the area.
"Our boys are preparing for a new wave," Mr Barabash told national television.
Ukraine's ground forces said Russia was also focused on Kupiansk - a city in the northeast overrun by Russia in the early days of the invasion, but recaptured by Ukrainian forces last year.
Moscow said today its forces had conducted successful attacks near the town of Bakhmut.
Avdiivka, where a vast fuel plant is located, was briefly captured in 2014 when Russian-backed separatists seized chunks of land in the east.
