New Delhi, Dec. 12 -- In the eastern Ukrainian town of Siversk, Russian forces announced on Friday that they had gained control after prolonged fighting. Moscow's Defense Ministry stated troops had raised the Russian flag over key administrative buildings following steady advances. Ukrainian officials countered that their defenders maintain positions in the area, amid ongoing clashes on day 1,387 of the conflict.

In the Donetsk region town of Siversk, situated on elevated terrain along important supply routes, control of the area has become a focal point in Russia's ongoing campaign in eastern Ukraine. Developments around Siversk may influence military movements toward the city of Pokrovsk, about 20 miles to the south, where intense mech...