KYIV - Russian forces were establishing positions inside the Ukrainian border town of Vovchansk in the northeastern Kharkiv region on Wednesday and fighting there was intense, the local police chief said.

The capture of the town 5 kilometres (3 miles) from the border would be Russia's most significant gain since it launched an incursion into the Kharkiv region on Friday, opening a new front and forcing Kyiv to rush in reinforcements.

"The situation is extremely difficult. The enemy is taking positions on the streets of the town of Vovchansk," Oleksiy Kharkivskiy, Vovchansk's patrol police chief, said on Facebook.

Ukraine's military said on Tuesday its forces pulled back to "more advantageous" positions in two areas of the Kharkiv region, including the Vovchansk area.

It cited "a consequence of enemy fire and storming action" and said the decision was taken "to preserve the lives of our servicemen and avoid losses."

  - Reuters