Authorities in northern Mali said at least four rebels were killed after a Dutch attack helicopter with the UN mission fired upon their car, Fox News reported.
The violence took place near Tabancort north of the town of Gao and is the first time that the UN mission, known as MINUSMA, carried out such air strikes.
Alhousseini Ag Goumeye, a military official with the Tuareg separatist rebel group NMLA, said six missiles were fired on the car, killing four militants.
In a statement, MINUSMA said its forces had to fire after they came under "direct heavy fire." It said the action was in line with its mandate to use force to protect civilians and urged the rebels to respect a cease-fire.