Rishi Sunak has accused Russia’s President Vladimir Putin of showing “utter contempt” for the international order as Western leaders vowed to establish how a missile came to hit a Polish village close to the Ukrainian border.

Speaking at the end of the G20 summit in Bali, the Prime Minister said there were already teams on the ground trying to work out what happened, amid reports it may have been a Ukrainian missile fired in defence against a Russia attack.

However, Mr Sunak stressed that the incident took place against a barrage of more than 80 Russian missiles launched against civilian infrastructure in Ukraine.

“That was happening at a time when the G20 was gathered trying to find resolution to some of the world’s challenges and the same time Putin was raining down indiscriminately that volume of missile attack,” he said.

“I think it shows utter contempt for the international rules-based system.”

Earlier, US President Joe Biden, who was also attending the gathering on the Indonesian island, said the trajectory of the missile flight suggested it was “unlikely” to have been fired from Russia.

As news of the missile hit killing two people broke, Mr Sunak joined other G7 and Nato leaders present at the summit in Bali for an emergency session convened by the US president.

Police officers work outside a grain depot where a missile killed two people in Przewodow
Police officers work outside a grain depot where a missile killed two people in Przewodow (Michal Dyjuk/AP)

The Prime Minister also spoke by telephone to both Polish President Andrzej Duda and Ukraine’s President Volodymyr Zelensky.

The Ukrainian leader condemned the hit as “a very significant escalation” of the war against his country by Russia, but Moscow vehemently denied any involvement in the incident.

A deliberate attack on a Nato member such as Poland would risk drawing the Western alliance into war, bringing it into direct conflict with Russia.

However, US officials cited by the Associated Press news agency said preliminary assessments suggested the missile was fired by Ukrainian forces at an incoming Russian missile.

Rishi Sunak with Canadian Prime Minister Justin Trudeau and US President Joe Biden at an emergency meeting of Western leaders during the G20 summit
Rishi Sunak with Canadian Prime Minister Justin Trudeau and US President Joe Biden at an emergency meeting of Western leaders during the G20 summit (Leon Neal/PA)

At his closing press conference, Mr Sunak stressed that none of this would be happening if it was not for Russia’s illegal invasion of its neighbour.

“This is the cruel and unrelenting reality of Putin’s war,” he said.

“The persistent threat to our security and global asphyxiation has been driven by the actions of the one man unwilling to be at this summit – Vladimir Putin.

“There isn’t a single person in the world who has not felt the impact of Putin’s war.”

Downing Street said that in his call with Mr Duda, the Prime Minister offered “any assistance needed” to help with the investigation.

President of Poland, Andrzej Duda during an earlier visit to Downing Street
President of Poland, Andrzej Duda during an earlier visit to Downing Street (PA)

“The leaders agreed to remain in close contact and continue co-ordinating with our international partners, including Nato allies, on the next steps,” a spokesman said.

As the Polish foreign ministry announced it was raising its level of military preparedness, the president said the missile was “most probably” Russian-made although its origins were still being verified.

“We are acting with calm. This is a difficult situation,” he said.

Even if the missile is confirmed as being of Russian origin, it would not necessarily mean it was fired by Moscow’s forces because Ukraine still has stocks of former Soviet and Russian-made weaponry.

Meanwhile, Nato secretary-general Jens Stoltenberg has called a meeting of the alliance’s ambassadors in Brussels while the UN Security Council in New York is also due to discuss the situation.

Polish media said the missile hit an area where grain was drying in Przewodow, a village near the border with Ukraine.

The Russian defence ministry denied being behind “any strikes on targets near the Ukrainian-Polish border” and said in a statement that photos of purported damage “have nothing to do” with Russian weapons.

The hit came as Russia pounded Ukraine’s energy infrastructure with its biggest barrage of missiles yet, striking targets across the country and causing widespread blackouts.