The Nigerian army says Boko Haram fighters have attacked a military base in the north-east of the country.
Reports say the heavily armed militants, driving in trucks mounted with guns, stormed the military location in the town of Damasak in Borno state on Wednesday evening.
The troops then responded, prompting an exchange of fire, which lasted for several hours.
There are no details about casualties.
This attack is the third major action by the militants in just a week.
A Boko Haram faction known as the Islamic State's West Africa Province (Iswap) had said its fighters killed several Nigerian soldiers in the two previous attacks.
The two factions of Boko Haram have stepped up attacks mainly on military targets, seizing weapons and inflicting heavy casualties on the army in recent months.
There are growing concerns over security as Nigeria prepares for general elections next February.
Boko Haram joined Islamic State in 2015 adopting the name Islamic State in West Africa Province.
But a faction of Boko Haram pulled out from the alliance in 2016 following a leadership crisis.