NUSA DUA, INDONESIA -- Prime Minister Justin Trudeau is extending Canada's training mission of Ukrainian soldiers after reports that a missile killed two people in Poland on Tuesday, though world leaders are urging calm as early findings suggest it was not an intentional attack.

"There is no confirmation of exactly what happened yet; there needs to be a proper investigation," Trudeau told reporters Wednesday on the sidelines of the G20 in Bali, Indonesia.

"One thing is absolutely clear, whether it was direct or indirect responsibility, Russia is responsible for what happened."

British Prime Minister Rishi Sunak, speaking to reporters alongside Trudeau, urged calm while an investigation takes place.

"I think the right thing now is for everyone to just calmly ascertain exactly what happened, gather the facts," he said.

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

Polish President Andrzej Duda said there are no signs that the blast was a deliberate attack.

"Ukraine's defence was launching their missiles in various directions and it is highly probable that one of these missiles unfortunately fell on Polish territory," said Duda. "There is nothing, absolutely nothing, to suggest that it was an intentional attack on Poland."

G7 leaders held an emergency meeting while attending the G20 summit in Indonesia Wednesday, after which they issued a statement condemning "the barbaric missile attacks Russia perpetrated on Ukrainian cities and civilian infrastructure."

Trudeau also announced that a mission to train Ukrainian soldiers will be extended until the end of 2023. The training takes place in Britain as part of Operation Unifier, which has been ongoing since 2015. The extension comes just days after Canada pledged another $500 million to support Ukraine's military.

In Ottawa Wednesday, Canadian Defence Minister Anita Anand said Canada was also sending another $34 million of equipment to Ukraine including additional drone cameras, winter clothing, and satellite communications technology.

She said earlier in the day she attended a virtual meeting of NATO's Defence Contact Group, which includes defence ministers and chiefs of defence to co-ordinate support for Ukraine.

She wouldn't comment on what she thinks happened in Poland pending the outcome of a full investigation.

"I will say that Canada has offered to support that investigation and we will continue to be with Ukraine in the short and the long term, because this is an unjustifiable and illegal war exacted by Vladimir Putin," Anand said.

NATO Secretary-General Jens Stoltenberg said there is "no indication that this was the result of a deliberate attack" but he said Russian President Putin's war is still to blame.

"This is not Ukraine's fault. Russia bears ultimate responsibility," Stoltenberg said.

Trudeau said he and Sunak echoed that sentiment in a conversation with Ukrainian President Volodymyr Zelenskyy Wednesday.

"We stressed the importance of a full investigation into what happened in Poland and we made it clear that Putin's invasion of Ukraine is ultimately to blame for this violence," Trudeau said.

The missile landed in Poland in the midst of a barrage of missile attacks from Russia into western Ukraine near the Polish border, that hit Ukraine's power grid and also cut electricity to much of Moldova.

Ukrainian air defences worked furiously against the Russian assault, with the Ukrainian military saying 77 of the more than 90 missiles fired were brought down, along with 11 drones.

The Associated Press first reported Tuesday that two sources, including a U.S. intelligence official, said the Polish blast was the result of a Russian missile.

Zelenskyy decried the Polish missile blast as a "very significant escalation" in the Russian war in Ukraine. Then the Polish government said that it had summoned the Russian ambassador on Tuesday and "demanded immediate explanations."

But following the G7 meeting in Indonesia, U.S. President Joe Biden said the missile was unlikely to have been fired from Russia. Poland later said it was "highly probable" the missile came from Ukraine.

That assessment appeared to reduce the chance of a major escalation in the ongoing war sparked by Russia's invasion of Ukraine in February. A deliberate attack could have risked involving NATO in the conflict, because Poland is an alliance member.

A keystone of the NATO alliance is Article 5, which stipulates that any "armed attack" against one member constitutes an attack against all, and may trigger a self-defence response from allies as a bloc.

Had Tuesday's events been determined to be deliberate, it was unclear whether they would fall under that category, or if they may fall under Article 4, which says member states can convene a consultation with other members if they feel their security or independence are threatened.

The Kremlin on Wednesday denounced Poland's and other countries' reaction to the missile incident as "hysterical" and, in rare praise for a U.S. leader, hailed the "restrained and much more professional" reaction of the U.S.

"We have witnessed another hysterical, frenzied, Russophobic reaction that was not based on any real data," Kremlin spokesman Dmitry Peskov told reporters on Wednesday.

-- With files from Marie-Danielle Smith, Lee Berthiaume, and Mia Rabson in Ottawa and The Associated Press

This report by The Canadian Press was first published Nov. 16, 2022.