Russian officials warn that the Ukraine war is entering the most dangerous phase to date and President Vladimir Putin has repeatedly warned of the risk of a much broader war involving the world’s biggest nuclear powers.

But directly blaming the US for a deadly attack on Crimea – which Russia annexed in 2014 and now considers to be Russian territory although most of the world considers it to be part of Ukraine – is a step further.

“We perfectly understand who is behind this,” Kremlin spokesman Dmitry Peskov told reporters, adding that it was clear who supplied such weapons, aimed them and provided data for them.

“Everything is absolutely clear here. As representatives of the media, you should ask my colleagues in Europe, and above all in Washington, the press secretaries, why their governments are killing Russian children. Just ask them this question.”

The Russian defence ministry said yesterday that the US was responsible for the attack on the city of Sevastopol.

Footage on Russian state television showed people running from a beach and some people being carried off on sun loungers.

Asked what Moscow’s response would be, Peskov recalled Putin’s words on June 6 when the Kremlin chief said he could deploy conventional missiles within striking distance of the US and its European allies if they allowed Ukraine to strike deeper into Russia with long-range western weapons.

“Of course, the involvement of the US in the fighting, as a result of which peaceful Russians are dying, cannot but have consequences,” Peskov said.

“Which ones exactly – time will tell.”