Two people were killed Tuesday in Poland near the Ukraine border by missiles suspected of being fired by Russian forces.

A U.S. official said the missiles crossed into NATO member Poland, where two people were killed, according to the Associated Press. 

The deaths occurred on the same day Russia launched a barrage of air strike across Ukraine, including on the capital city of Kiev, which as a result has been left without power and in darkness.

In response, Polish government spokesperson Piotr Muller said the prime minister is calling for an urgent national security and defense meeting.