Belarus has deployed additional air defence forces to its border with Ukraine to protect "critical infrastructure facilities" due to increased Ukrainian drone activity in the area, a Belarusian military commander said on Saturday.

Belarus, an ally of Russia in the war with Ukraine, said earlier this week it had shot down a quadcopter that had illegally crossed the border from Ukraine "to collect information about the Belarusian border infrastructure".

The situation in the airspace over the border remains tense, Andrei Severinchik, commander of the Belarusian Air Defence Forces, said on Saturday.

"We are ready to decisively use all available forces and means to protect our territory and the population of the Republic of Belarus from possible provocations in the airspace," he said in a statement published on the Defence Ministry's Telegram channel.

The Defence Ministry said earlier on Saturday it had information showing Ukraine had been moving more troops, weapons and military equipment to the northern Zhytomyr region, which borders Belarus.

There was no immediate comment from Ukraine.

  - Reuters