A large attack by Islamic State West Africa Province (ISWAP) fighters on an army base in Nigeria killed 22 troops before the army was able to push the terrorists back across the border into Niger, the Nigerian army reported on Monday.

The ISIS-aligned fighters attacked the remote Nigerian army base in Burkusuma, in Nigeria’s northwestern Sokoto State in the early morning hours of Sunday. The base is close to the border with Niger. 

Major General Benjamin Sawyerr, a senior Nigerian army spokesman, said that the troops repelled the attack and killed a large number of ISWAP fighters, forcing them to withdraw back across the border toward the remote town of Bassira. The terrorists are now being pursued by Nigerian and Nigerien troops working together, Sawyerr added.

“The failed attack … was swiftly repelled by troops,” Sawyerr said. “Unfortunately, there was some level of casualties recorded on the part of own troops during the encounter,” he added without delving into specific casualty counts.