Polish Foreign Minister Radoslaw Sikorski has said that he had asked the Israeli ambassador in Warsaw for “urgent explanations” after a strike killed a Pole and six other aid workers in Gaza, AFP reports.

“I personally 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 said Poland would open its own inquiry into the aid worker’s death.

“Poland does not accept the lack of compliance with international humanitarian law and of the protection of civilians, including humanitarian workers,” the Polish foreign ministry said Tuesday. It did not provide the name of the Polish citizen who died.

Polish President Andrzej Duda also expressed condolences to the aid worker’s family, adding on X that “this tragedy should never have happened and must be explained”.