Nigerien Defence Ministry on Friday said a joint military operation between Chad and Niger has killed 123 Boko Haram militants since July and recovered a significant quantity of weapons.

The Chadian-Nigerien forces launched an offensive against the Islamists after a surprise attack in Niger killed 30 of the country’s troops in early June, its deadliest ever attack there.

According to Defence ministry spokesman Colonel Moustapha Ledru, 14 of the two nations’ own troops had also died and 39 had been wounded in fighting with the Nigerian militant group over the same period.

“An important quantity of arms and weapons were recovered,” he said.

They targeted the Diffa region, which lies just across the border from the Islamists’ stronghold in northeastern Nigeria.

The spokesman also said that the “terrorists” who had been killed had “infiltrated” into Diffa from Nigeria, adding that two fighters had been captured.

Boko Haram has been waging a war to establish an Islamist caliphate around the Lake Chad region, where Nigeria, Cameroon; Niger and Chad meet.