Polish officials closed the crossing with Belarus at the border town of Kuznica on Tuesday morning, a day after thousands of migrants arrived in the area seeking to cross into the EU.
Poland's Prime Minister Mateusz Morawiecki described the incident as a "hybrid attack" conducted by the regime of Belarus President Alexander Lukashenko.
"Sealing the Polish border is our national interest. But today the stability and security of the entire EU is at stake," Morawiecki wrote on Twitter.
"We will not be intimidated and will defend peace in Europe with our partners from NATO and EU."
The EU claims Lukashenko is attracting migrants from the Middle East to Belarus with special visas and taking them to the border with EU and NATO members Poland and Lithuania.
What has Poland said?
Polish President Andrzej Duda said about 1,000 people, "mostly young men" are camped out on the Belarusian side of the border.
"The Belarusian regime is attacking the Polish border, the EU, in an unparalleled manner," he said. "These are aggressive actions that we must repel, fulfilling our obligations as a member of the European Union."
A spokesman for Poland's security services, Stanislaw Zarin, also accused Belarus security forces of "firing empty shots into the air" and helping migrants attack the barrier.
"We see how they bring them tools to cut wires... to destroy the fence."
DW correspondent in Poland, Magdalena Gwozd-Pallokat, said the situation was "getting explosive" with both Poland and Belarus amassing troops at the border and unconfirmed reports of people from Belarus seen on the Polish side of the border.
Polish border troops have already warned they would "use any necessary means they can if there is such a need," she said.
What is the response from Belarus?
Belarus denied the Polish accusations, labeling them as "unfounded and unsubstantiated," and claimed Warsaw was deliberately escalating tensions.
"We would like to warn the Polish side in advance against using any provocations directed against Belarus to justify possible illegal forceful actions against disadvantaged unarmed people, among whom there are plenty of underage children and women," it said.
Border officials also said Poland was deploying military equipment and blocking aid workers from accessing the area.
They added Poland had no legitimate reason to close down the border crossing, saying that the decision might have been made so that the Polish side can "eliminate video footage from bystanders" and hide potential use of force or weapons against the migrants.
With tensions rising as both Poland and Belarus deploy thousands of soldiers to the border region, Lukashenko said his country was "not looking for a fight."
"I am not a madman, I understand perfectly well where it can lead... We understand, we know our place. But we will not kneel," he told Belarusian state news agency Belta.
Lukashenko also said that it was international human traffickers who were transporting migrants into Belarus, but that it was completely legal for them to enter the country.
"They have discovered a gap here," he told state media.
Also on Tuesday, Lukashenko talked to Russian President Vladimir Putin about "disturbing facts and trends" on the Belarusian-Polish border. This included Poland's "severe response against civilians."
What is the current situation at the Poland-Belarus border?
Hundreds of migrants are believed to still be near the border on Tuesday, with videos showing tents and fireplaces on the Belarusian side. The Polish Interior Ministry said the night was quiet, save for a rock being thrown at a police car.
Videos from the scene on Monday showed a large group of migrants attempting to breach the border. Polish border guards and military claim Belarus troops were controlling and directing the group.
Polish government spokesman Piotr Muller told reporters that another 3,000 to 4,000 migrants were massing in the area.
"We expect that there may be an escalation of this type of action on the Polish border in the near future, which will be of an armed nature," he added.
Russia urged all sides to act responsibly, with the Kremlin spokesman Dmitry Peskov saying that Moscow was watching the situation "very closely."
The first priority, according to Peskov, are "the lives and health of this large number of people gathered at the border."
Meanwhile, Russian Foreign Minister Sergey Lavrov hinted at the EU giving financial aid to Belarus to stem the migrant flow, referencing an existing deal with Turkey.
What about the migrants?
Polish activist Magdalena Luczak from the Grupa Granica aid group told DW that migrants are "terrified" and don't know what is going on.
"They hope that somebody will help them cross the border and take them to a safe place. Today, some of them meant Germany, others meant some other European countries. But it's not only that, because many people would like to stay in Poland but they are afraid they are not able to, that they would not get asylum."
She also urged the EU to pressure Warsaw into allowing aid workers into the area.
"Look, there is terrible weather right now. Tonight, the whole night it was the rain and in the morning was frost," she told DW. "And those people are without food, without water, without shelter. Nothing. Just I don't know how to survive in such conditions in the forest."
The AFP news agency cited migrants who made it into Poland last month as saying they were trapped in the woods for a week. Belarus officials were refusing to let them travel to Minsk and fly home, while Polish security forces refused to let them cross and ask for asylum.
How has the EU reacted?
Responding to the crisis, the EU Council said it was suspending part of a visa facilitation agreement affecting Belarusian officials.
"This decision will not affect ordinary citizens of Belarus, who will continue to enjoy the same benefits under the visa facilitation agreement as they do currently," they said in a statement.
"It is unacceptable for Belarus to play with people's lives for political purposes," said EU Council representative Ales Hojs.
"This is part of the inhuman and really gangster style approach of the Lukashenko regime," a European Commission spokesman, Peter Stano, told journalists.
He added that the EU was considering new sanctions against Lukashenko's allies.
Previously, Commission chief Ursula von der Leyen said the EU was looking into sanctioning airlines who are "active in human trafficking" by flying migrants from their home countries into Belarus.
France said it was ready to review a "reinforcement" of EU sanctions at next week's summit of the bloc's foreign ministers.
The Lithuanian government has proposed introducing a state of emergency at the border region which would start on midnight, pending approval by the country's parliament.
What did German interior minister say?
German Interior Minister Horst Seehofer called on EU countries to "stand together" and accused Lukashenko and his Russian ally Vladimir Putin of trying to destabilize the West.
"The Poles have reacted correctly so far,'' Seehofer told German mass-circulation daily Bild. "We cannot criticize them for securing the EU's external border with admissible means. The Poles are fulfilling a very important service for the whole of Europe.''
The minister also urged the EU Commission to help Warsaw's efforts.
"We must help the Polish government secure their external border," he said.
However, the Polish authorities have so far refused the offers of additional assistance from the EU.
How are migrants getting to the border?
Since July, large numbers of migrants from Iraq, Syria, Yemen and other troubled regions have been attempting to illegally enter the EU via Poland, Latvia and Lithuania. According to reports, the trips can cost between €12,000 to €15,000 ($14,000 to $17,000), including visas, flights and being smuggled overland once in Europe.
On Tuesday, EU Commissioner for Home Affairs Ylva Johansson said that the current border standoff is "unprecedented."
According to the commissioner, Belarus is luring potential migrants by promising them a safe journey to the EU. After arriving in Minsk, newcomers spend some time in hotels before heading toward the border, accompanied by people wearing the uniforms of the Belarusian army.
Before leaving, however, the migrants are required to pay a deposit which they would allegedly be allowed to collect if they do not make it into the EU, Johansson said.
But once the final stage of the journey starts, Belarusian authorities no longer allow migrants to go back — instead, pushing them toward the bloc, Johansson added.
dj/rt (AFP, Interfax, Reuters)