Mozambique security forces killed at least 129 insurgents in the northern region Cabo Delgado that has been plagued by violence for at least the last three years, the interior minister said on April 28.

Since 2017, infrequent but violent raids on government buildings and villages by armed groups with suspected links to the Islamic State (ISIS) have intensified in northernmost province of one Africa’s poorest nations.

The interior ministry said the 129 killings were the total for the month, and were a retaliation for an attack in Xitaxi in Muidumbe district earlier in April, where insurgents killed 52 villagers.

The insurgents profile reamins obscure, though initial attacks were claimed by a group known as Ahlu Sunnah Wa-Jama. More recently, Islamic State (IS) has claimed a number of attacks.