Migrants camping in freezing weather on the border between Poland and Belarus face worsening conditions as the European Union and Russia have become involved in the increasingly tense standoff.

A group of migrants mostly from the Middle East and Africa seeking to relocate to Europe have gathered on Belarus’ western border with Poland. Belarus’ authoritarian leader Alexander Lukashenko has encouraged the migrants to enter Poland, illegally if necessary. Polish forces are blocking the migrants’ entry into the country sealing off a stretch of the border with barbed wire.

Western leaders have accused Lukashenko of treating the migrants as pawns in a scheme to manufacture the crisis along its border in retaliation for economic sanctions imposed on Belarus for his heavy-handed rule of the country.

“What we are dealing with is a new type of war,” Polish Prime Minister Mateusz Morawiecki said in a statement Thursday. “This is a war in which civilians and the media are ammunition.”

His remarks came on Polish Independence Day, noting the struggle the country, now a member of the European Union, faced against Russian aggression over a hundred years ago. Although Morawiecki’s right-wing government has clashed with Brussels, he said on Twitter that Poland will “not be intimidated and will defend peace in Europe with our partners from NATO and EU.”

European Union Commission President Ursula von der Leyen said on Twitter Wednesday that after meeting with President Joe Biden the allies would move forward next week on additional sanctions against Belarus over the situation at the border.

“This is a hybrid attack,” she said. “Not a migration crisis.”

Lukashenko shot back, threatening to cut off a key gas line to Europe.

“We furnish Europe with heat, yet they threaten to close the border. And what if we shut off natural gas there?” Lukashenko said, according to Russian news agency Tass, citing Belarusian state media. “Therefore, I would recommend that the Polish leadership, the Lithuanians and other empty-headed individuals think before they speak.”

German Chancellor Angela Merkel on Wednesday asked Russian President Vladimir Putin to “exert influence” over Belarus, a former Soviet republic closely aligned with Russia. During the call, Putin said the EU should directly engage with Belarus to resolve the problem, according to the Kremlin.

But on Thursday, Russian and Belarusian forces said they would carry out joint military exercises along the border of Poland, the Baltic states and Ukraine, reports Tass. The exercises would include bombers capable of carrying nuclear weapons.

“Indeed, the rise in tensions on this border where highly armed people — meaning the military — are present on both sides is a matter of utmost concern to all sober-thinking people in Europe,” a spokesman for Putin said Thursday, The New York Times reported, citing Russian state media.

However, he warned of military escalation as troops gathered on both sides.

Meanwhile, trapped between the two countries’ armed forces, migrants have faced freezing weather and increasingly desperate conditions.

“We became like a chicken in a cage in the hands of Belarusian and Polish police,” Bayar Awat, an Iraqi Kurd who has been stuck on the border with his wife and infant daughter for a week, told The New York Times. “One of them won’t let us go back to Minsk and the other won’t let us in. Belarus is playing with us any way they want.”

He described how his family abandoned their tent and sleeping bags because of the weight as they were led through a dense forest by Belarusian forces. He said he was beaten by Belarusian police and was met with tear gas and water cannons by Polish security.

Awat, one of several thousand migrants from Iraq’s Kurdistan, said he was aware he was being used by Belarus but was holding out for admittance to the European Union.

Youssef Atallah, a 37-year-old Syrian, told CNN that he arrived in Poland after his third attempt to cross from Belarus. He described being beaten by Belarusian guards suffering facial injuries, a broken nose and bruised ribs. He said he was denied medical care and told to make the journey with no food, forcing him to drink water from a swamp.

Poland’s Ministry of National Defence said on Twitter Wednesday that 15,000 soldiers are protecting its border from what it characterized as an “attack” from Belarus.

The ministry said in a separate tweet that a soldier fired warning shots into the air after a migrant threw a branch that struck him in the chest. In another tweet, the ministry accused Belarusian forces of firing shots in the air near migrants.

Migrants attempting to cross into Poland have received texts telling them the border is sealed and to go back to Minsk, the Belarusian capital, reports Al Jazeera.

At least 10 people have died, mostly on the Polish side, reports Al Jazeera. However, the Polish government has been reluctant to provide humanitarian relief and activists and aid workers expect more bodies to be found in the forest. Journalists and NGOs have been unable to access the border area because of a state of emergency declared by the Polish government.