US President Joe Biden has said it is "unlikely" that a rocket that killed 2 radical successful Poland connected Tuesday was fired from Russia.
Polish officials said the "Russian-made missile" landed successful Przewodow, connected the Ukrainian border.
Early reports had suggested Russia was to blasted for the blast. Moscow denied the allegations.
Speaking from the G20 Summit successful Bali, Mr Biden said "preliminary information" contested the reports.
The US President was speaking aboriginal connected Wednesday morning, aft respective satellite leaders gathered connected the broadside lines of the acme astatine an "emergency roundtable" to sermon the blast.
Among the attendees were President Biden, UK Prime Minister Rishi Sunak, French President Emmanuel Macron and EU Commission President Ursula von der Leyen.
Reports of the missiles falling successful Poland - which is simply a Nato subordinate - came aft Russia launched a caller question of attacks crossed Ukraine connected Tuesday, days aft its troops were forced to permission Kherson.
Russia dismissed claims it was responsible, with the defence ministry successful Moscow attacking what it called "a deliberate provocation aimed astatine escalating the situation".
Kremlin spokesperson Dmitry Peskov besides said helium had nary accusation connected the blast.
Russian authorities quality bureau Ria Novosti said it was alternatively Ukrainian missiles that had deed Polish territory.
But Ukraine's Foreign Minister Dmytro Kuleba said immoderate assertion that Ukraine was liable was a Russian "conspiracy theory", and that anyone amplifying the connection was spreading "Russian propaganda".
Polish President Andrzej Duda told reporters that it remained unclear however the blast had occurred, and said investigators were evaluating each possibilities.
"We bash not person immoderate conclusive grounds astatine the infinitesimal arsenic to who launched this rocket … it was astir apt a Russian-made missile, but this is each inactive nether probe astatine the moment," helium said.
Images shared online showed what appeared to beryllium a ample crater connected what section media reported was Polish farmland, suggesting rocket damage. Another representation appeared to amusement a fragment of a missile.
The encroachment onto Polish territory raised questions arsenic to whether Warsaw would trigger nonfiction Four of the Nato pact - meaning subordinate states consult connected whether the territorial integrity, governmental independency oregon information of immoderate subordinate authorities is threatened.
Warsaw said it was considering whether to invoke the provision.
Despite lending enactment to Ukraine since Russia's invasion, Nato has been cautious not to go excessively heavy progressive successful the struggle successful bid to forestall an escalation.
G7 besides released a connection condemning the "barbaric rocket attacks" launched by Russia connected Tuesday, and addressing the "explosion" successful Ukraine.
"We connection our afloat enactment for and assistance with Poland's ongoing investigation. We hold to stay successful adjacent interaction to find due adjacent steps arsenic the probe proceeds," it said.
Meanwhile United Nations Secretary General Antonio Guterres besides said helium was "very concerned" by the Poland explosion, and called for a thorough investigation.
"It is perfectly indispensable to debar escalating the warfare successful Ukraine," his spokesperson Farhan Haq said.
The BBC's Paul Adams said determination were a fig of imaginable explanations for the incident.
Russia has nary involvement successful targeting Polish farms, truthful immoderate benignant of malfunction seems possible, helium said. And, connected a time erstwhile Ukraine's aerial defences were moving hard to bring down Russian missiles, it is besides imaginable that 1 of those missiles was knocked disconnected course, our analogous adds.
Nato Secretary General Jens Stoltenberg said helium had spoken to Polish President Andrzej Duda and the subject confederation was "monitoring the situation".
"Allies are intimately consulting," helium said connected Twitter. "Important that each facts are established."
The attacks came aft 1 of the heaviest bombardments of Ukraine by Russian forces since the warfare began.
Ukraine was deed by implicit 90 missiles connected Tuesday, according to Ukraine's Air Force spokesperson Yuri Ihnatw, who said much than 70 were successfully changeable down.
Ukrainian President Volodymyr Zelensky said astir of the rockets fired had been aimed astatine the country's vigor infrastructure.