Belarus, an ally of Russia, said earlier this week that 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 Defense Ministry’s Telegram channel.

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