Dutch Defence Minister Jeanine Hennis resigned late Tuesday in the wake of a damning report over the death of two soldiers killed in an accidental mortar explosion in Mali last year.

"I am politically responsible and am taking that responsiblity," Hennis told the lower house of parliament in The Hague.

"I resign as minister and will ask his majesty the king for my immediate release," she said after more than four hours of parliamentary debate over the deaths of the two men who served as UN peacekeepers in the troubled west African state.

General Tom Middendorp, the top Dutch military commander, also tendered his resignation Tuesday over the incident.

Kevin Roggeveld, 24, and Henry Hoving, 29, were killed "outright" in July 2016 and a third soldier was seriously wounded by shrapnel in Kidal, northwest Mali, when a mortar shell unexpectedly went off during a live-fire exercise.

Hennis, one of the most senior members of Prime Minister Mark Rutte's liberal VVD party, quit just days before Rutte is to announce a new government in which she was expected to play a central role.

But she has come under increased political pressure since the Dutch Safety Board (OVV) released last Thursday its final report on the incident, which denounced "serious shortcomings" leading to the two soldiers' deaths.

In its report, the board found the military had been using stocks of old shells bought in 2006 "with the help of the US Department of Defence amid a pressure of time."

During the munitions purchase, the Dutch defence ministry "omitted to carry out its own procedures and controls... as it assumed the US Army was already using the ammunition and had carried out safety tests," the OVV said.

It found that the shell "had weak spots in its design which allowed water to penetrate," and the moisture combined with heat meant the stock was "unstable and shock-sensitive."

Even though the round was correctly loaded, it exploded inside the mortar tube, investigators found.

The report also said that while the injured soldier had received satisfactory emergency treatment on site, he was later transferred to a Togolese hospital "which did not meet Dutch military guidelines."

The Netherlands has been part of the UN stabilisation mission in Mali (MINUSMA) since April 2014, and has deployed about 400 troops, four Apache and three Chinook helicopters to the restive west African nation, Dutch media has reported.

Since being deployed there, 80 UN peacekeepers have been killed, making it the most costly UN mission in terms of human life since Somalia (1993-1995).