Russia has said it has taken full control of the eastern Ukrainian city of Avdiivka, its biggest gain since capturing Bakhmut last May, after a retreat by Ukrainian troops.

Ukrainian forces had withdrawn from the city in the industrial Donbas region to avoid encirclement, the army chief, Oleksandr Syrskyi, said on Saturday, adding that he had acted to “preserve the lives and health of servicemen”, stabilise the situation and move troops to more favourable defence lines.

Some Ukrainian troops were still holed up in a vast Soviet-era coke plant, one of Europe’s biggest, Russia said, describing the retreat as rushed and chaotic.

Ukraine’s military said there had been casualties in the retreat but that the situation had stabilised.

The capture of Avdiivka gives Russia full control of the area surrounding Donetsk, a large Ukrainian city that was seized by Russian proxy forces in 2014, and comes as the second anniversary of its full-scale invasion of Ukraine nears.