Nigerien authorities on Thursday announced that its Air Force recorded its biggest counter-insurgency success in eight months after arresting over 20 militants in a raid of a Boko Haram base in the south eastern region of the country.

Niger’s southern border region of Diffa is an area repeatedly suffering attacks from the Islamist militant group based mostly in North eastern Nigeria.

The Nigerien forces have continued to trail the militants after a soldier was killed when a military vehicle was blown up by remote control by the group near Lake Chad on Monday.

“Our air forces destroyed this nest, but we do not yet have an official death toll,” a military officer said, but added that its soldiers had arrested the remaining fighters.

In October, Niger’s parliament approved a three-month extension of a 15-day state of emergency in Diffa region in order to boost security.

According to a top UN official, a 8,700 regional task force is set to begin joint raids on Boko Haram’s last enclaves when the rainy season ends soon.