A Russian missile entered Polish airspace on Sunday as the Russian military launched a wave of airstrikes against Ukrainian targets in the wake of a deadly terrorist attack against civilians at a Moscow concert hall.

Russian forces launched 57 missiles against Ukraine, at least one of which flew through Polish airspace before reaching its target. Poland says it activated its own aircraft and other countermeasures following the incursion.

Top Polish officials said Sunday they will «demand explanations from Russia in connection with another violation of the country’s airspace.»

«Above all, we call on the Russian Federation to stop terrorist air attacks on the inhabitants and territory of Ukraine,» the Polish Foreign Affairs Ministry said in a Sunday statement.

RUSSIA INVESTIGATING SHOOTING, EXPLOSIONS AT CONCERT HALL AS TERRORIST ATTACK

A Russian missile entered Polish airspace on Sunday as the Russian military launched a wave of airstrikes against Ukrainian targets in the wake of a deadly terrorist attack against civilians at a Moscow concert hall. (Getty Images)

The weekend missile strikes on Ukraine come after Russian President Vladimir Putin claimed that the culprits in a deadly Moscow terrorist attack attempted to flee to Ukraine after the shootings on Friday.

SOCCER MATCH BETWEEN RUSSIA AND PARAGUAY CANCELED IN AFTERMATH OF MOSCOW-AREA CONCERT HALL ATTACK

The death toll in Friday’s terror attack on a concert in Moscow has soared to at least 133, Russia’s top state investigative agency said Saturday, with authorities saying they have apprehended 11 suspects, four of whom were reported to be directly involved in the onslaught.

While Ukraine has denied any involvement, Putin says the four alleged attackers were trying to cross the border via a «window» prepared for them by Ukraine.

Russian President Vladimir Putin claimed that the culprits in a deadly Moscow terrorist attack attempted to flee to Ukraine after the shootings on Friday. (Sergei Savostyanov/Pool/AFP )

«All four direct perpetrators of the terrorist attack, all those who shot and killed people, were found and detained,» Putin said. «They tried to hide and moved toward Ukraine, where, according to preliminary data, a window was prepared for them from the Ukrainian side to cross the state border.»

Russian authorities have identified the gunmen as migrants from Tajikistan, a former Soviet country bordering Afghanistan.

Russian authorities have identified the Moscow gunmen as migrants from Tajikistan, a former Soviet country bordering Afghanistan. (Sergei Vedyashkin/Moscow News Agency via AP)

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ISIS has claimed responsibility for the attack, though Putin did not mention the terrorist group during a speech addressing the tragedy.

Fox News’ Michael Dorgan and The Associated Press contributed to this report.