MOSCOW >> Russia sent paratroopers to Belarus today in a show of support for its ally amid tensions over migrants and refugees amassing on the Belarus-Poland border.

The Russian Defense Ministry said that as part of joint war games, about 250 Russian paratroopers parachuted from heavylift Il-76 transport planes into the Grodno region of Belarus, which borders Poland. It said the paratroopers re-boarded the transport planes and flew back to Russia after the exercise.

The Belarusian military said the exercise involving a battalion of Russian paratroopers was intended to test the readiness of the allies’ rapid response forces due to an “increase of military activities near the Belarusian border.”

It said the drills that involved Belarusian air defense assets, helicopter gunships and other forces envisaged targeting enemy scouts and illegal armed formations, along with other tasks.

Earlier this week, Russia sent nuclear-capable strategic bombers on patrol missions over Belarus for two straight days. Russia’s deputy U.N. ambassador, Dmitry Polyansky, told reporters at U.N. headquarters in New York that the flights came in response to a massive buildup on the Polish-Belarusian border.

Russia has strongly supported Belarus amid a tense standoff this week as thousands of migrants and refugees, most of them from the Middle East, gathered on the Belarusian side of the border with Poland in hopes of crossing into the European Union.

The EU has accused Belarus’ authoritarian president, Alexander Lukashenko, of encouraging illegal border crossings as a “hybrid attack” to retaliate against EU sanctions on his government for its crackdown on domestic protests after Lukashenko’s disputed 2020 reelection.

Belarus denies the allegations but has said it will no longer stop refugees and migrants from trying to enter the EU.

The Belarusian Defense Ministry has accused Poland of an “unprecedented” military buildup on the border, saying that migration control did not warrant the concentration of 15,000 troops backed by tanks, air defense assets and other weapons.

“I’d like to warn hotheads not to overestimate their capabilities,” Defense Minister Viktor Khrenin said today. “Language of ultimatums, threats and blackmail is not acceptable. Belarus armed forces are ready to respond harshly to any attacks.”

Russia and Belarus have a union agreement envisaging close political and military ties. Lukashenko has stressed the need to boost military cooperation in the face of what he has described as aggressive actions by NATO allies.