Defence ministry officials were aware there were risks attached to a decision to attack an IS bomb factory in Iraq in 2015, ministry documents show.

In total, 70 civilians died in the bombing, which ‘triggered a series of secondary explosions that reduced the surrounding area in the industrial district to rubble’, Reuters reported at the time.

Documents published following NRC and NOS freedom of information requests show military chiefs decided to press ahead with the bombing despite being told the impact  could be greater than indicated in the official collateral damage estimate.

The expected knock-on effect was ‘not excessive given the expected military advantage’, the defence ministry documents said.

The extent of the Dutch armed forces’ involvement in the attack only became clear last year.

Dutch F16s were used in Iraq and Syria between 2014 and 2016 and in 2018 as part of the international coalition against IS. In total they were involved with 2,100 bombing raids.

Dutch military operations are extremely sensitive to the possibility of civilian casualties since the Srebrenica massacre in 1998, and all involvement in military missions has to be cleared by parliament.