The bombing by Dutch F-16 fighter planes targeting the Islamic State group also caused hundreds of serious injuries and damaged thousands of homes and shops, said the study by the Utrecht University and NGO groups.

"The lack of an apology and actual reconstruction has a great impact on the perception of Hawija's residents," said the researchers, who spoke to 160 residents -- 119 of whom where victims -- after the attack.

"It contributes to an anti-Western sentiment and, according to the researchers, can form a breeding ground for the next terrorist organisation," it said.

The Dutch government acknowledged in 2019 that 70 people, including civilians and IS fighters had died after a munitions factory was bombed on the night of June 2 to 3, 2015.

The cabinet told the Dutch parliament that the targeted factory in an industrial zone contained more explosives than first believed.

The Netherlands promised a "voluntary" 4-million-euro ($4.3 million) package to help with reconstruction.

Hawija's residents felt abandoned and were demanding an apology from the Dutch government, they said.

The report recommended that Dutch government officials travel to Hawija to offer an apology and help to repair the damage.

The Dutch defence ministry said it was "not surprised" by the researchers' findings but did not react on the report's recommendations, the NRC daily newspaper reported.