The official spoke on condition of anonymity because of the sensitive nature of the situation, the AP reported. Reuters could not immediately confirm the information.

Firefighters in Poland said on Tuesday two people died in an explosion in Przewodow, a village in eastern Poland near the border with Ukraine.

Polish prime minister Mateusz Morawiecki has called an urgent meeting of a government committee for national security and defence affairs, the government spokesman said on Twitter.

Russia rained missiles on cities across Ukraine yesterday in what Ukraine said was the heaviest wave of missile strikes in nearly nine months of war, echoing a pattern in recent weeks of Moscow lashing out far from the front after battlefield losses.