Poland's deputy foreign minister Andrzej Szejna on Tuesday said that Israel should "compensate" the families of the seven aid workers, including a Polish citizen, killed in an Israeli strike in Gaza.
The World Central Kitchen, a US-based NGO that feeds communities affected by conflict, said seven members of its team were killed while working in the famine-threatened Gaza Strip.
"The authorities should think about who should be held criminally responsible for pressing a certain button and how to compensate the families of the victims -- even if it's impossible to do so with money," Szejna told Radio Zet.
Polish Foreign Minister Radoslaw Sikorski earlier said he had demanded "urgent explanations" from Israel's ambassador in Warsaw regarding the incident.
"I asked the Israeli ambassador Yacov Livne for urgent explanations," Sikorski said on social media, adding that he had offered "condolences to the family of our brave volunteer".
He also announced Poland had opened its inquiry into the aid worker's death.
"Our brave compatriot, Damian Sobol from the city of Przemysl, helped those in need in Gaza, where a humanitarian crisis is taking place," Sikorski said in a video published on X, formerly Twitter.
"He was killed in an attack for which the Israeli army claimed responsibility," Poland's top diplomat added.
He later held a phone call with his Israeli counterpart, Israel Katz.
World Central Kitchen said its team was traveling in a "de-conflicted" area in a convoy of "two armoured cars branded with the WCK logo and a soft skin vehicle" at the time of the strike.
"Poland does not accept the lack of compliance with international humanitarian law and (the lack) of the protection of civilians, including humanitarian workers," the Polish foreign ministry said on Tuesday.
Polish President Andrzej Duda also expressed condolences to the aid worker's family, adding on X: "This tragedy should never have happened and must be explained."
"These brave people changed the world for the better with their service and dedication to others," he wrote.
World Central Kitchen has announced it is pausing operations after the strike, which it said killed volunteers "from Australia, Poland, United Kingdom, a dual citizen of the US and Canada, and Palestine".