These operations involved widespread atrocities and the depopulating of the area to block the advance of guerillas, who relied on support from the local African populace.

By 1972, the Portuguese government deployed large amounts of Army units and PIDE/DGS corps to the area, with their behaviour and that of the settler militias becoming increasingly harsh.

[3] On 16 December 1972, the Portuguese 6th company of Mozambique Commandos killed the inhabitants of the village of Wiriyamu, in the district of Tete.

The soldiers were told by this agent that "the orders were to kill them all", never mind that only civilians, women and children included, were found.

Later counter-claims have been made in a report of Archbishop of Dar es Salaam Laurean Rugambwa that alleged that the killings were carried out by FRELIMO combatants, not Portuguese forces.