A SENIOR US intelligence official says Russian missiles crossed into Nato member Poland, killing two people.

Polish government spokesman Piotr Mueller did not immediately confirm the information, but said top leaders were holding an emergency meeting due to a “crisis situation”.

Polish media reported that two people died on Tuesday afternoon after a projectile struck an area where grain was drying in Przewodow, a Polish village near the border with Ukraine.

Speaking to the BBC, a source in the Polish prime minister's office said: "It's informational chaos."

"I have no certainty and I cannot confirm anything."

Meanwhile, the Pentagon has said it is "looking into" the reports.

The US Department of Defense press secretary Patrick Ryder said: “We are aware of the press reporting on this. We have no information at this time to corroborate those reports but again, are taking them seriously and looking into them. And so I will make sure that we provide you with any updates as soon as we have them.”

He added: “We're looking into these reports - don't have any information to corroborate them at this time. So I don't want to speculate or get into hypotheticals. When it comes to our security commitments and Article 5, we've been crystal-clear that we will defend every inch of Nato territory.”

And it is now understood that the UK Foreign Office is aware of the reports and urgently seeking clarity.

Commenting on the news, SNP MP Stewart McDonald tweeted: "Reports of Russian missiles hitting Poland and killing two people are extremely concerning, but we must await official information from the government of Poland after their national security community meets."

The reports come at the end of a day of heavy Russian bombardment on Ukrainian soil, with missiles targeting energy facilities and causing blackouts.

A senior official warned that the situation was “critical” and urged Ukrainians to “hang in there” as neighbourhoods went dark.

The aerial assault, which resulted in at least one death in a residential building in the capital, Kyiv, followed days of euphoria in Ukraine sparked by one of its biggest military successes in the nearly nine-month war - the retaking last week of the southern city of Kherson.

At least a dozen regions reported strikes, which caused multiple emergency blackouts.

A Ukrainian air force spokesman said Russia fired around 100 missiles. President Volodymyr Zelenskyy put the number at 85.

Zelenskyy warned that more attacks may be coming but defiantly vowed, with a shake of his fist: “We will survive everything.”