The Nigerian Army Chief of Staff visited troops stationed in the northeast of the country on Saturday, a few days after jihadists killed fifteen soldiers in the region.
Suspected Islamic State-aligned fighters killed 15 troops and five anti-jihadist militia members when they attacked and burnt down a military base in northeastern Nigeria's Borno state, according to defence and local sources.
Borno is the epicentre of more than 17 years of jihadist insurgency by Boko Haram -- and later its splinter group Islamic State in West African Province (ISWAP) -- which has killed thousands and displaced millions across northeast Nigeria.
The violence, which erupted in 2009, had eased from its peak a decade ago but has been on the rise over the past two years.
A large group of ISWAP fighters overran a military base in Mairari village in the Lake Chad area overnight from Tuesday to Wednesday, looted weapons and then burnt down the base, the sources said.
"The terrorists killed 15 soldiers and five civilian JTF (anti-jihadist militia) assisting the soldiers during the attack," a Nigerian military officer told AFP.
The militants "razed the base to the ground", forcing troops to withdraw towards the garrison town of Monguno, about 18 kilometres away, the officer said, asking not to be named because he was not authorised to speak publicly about the incident.
Several soldiers were missing, raising fears among their colleagues that they may have been captured by the jihadists, the military source said.
Grema Butari, a Mairari resident, said the fighters attacked the base around 2200 GMT, dislodged the troops after a "prolonged battle" and remained there until daybreak.
"They took everything of value they could carry and burnt the rest along with several vehicles," Butari said, giving the same death toll.
The jihadists were believed to have launched the attack from their base in Gudumbali, in neighbouring Guzamala district, said another resident, Ahmad Sherif, who also confirmed the "total destruction" of the base.
Rising violence
Nigeria is experiencing its most violent period in nearly three decades, with the second quarter of 2026 recording the highest level of violence since the Armed Conflict Location & Event Data (ACLED) project began tracking it in 1997.
Last week, around two dozen militants and soldiers were killed when ISWAP fighters attacked a military outpost in neighbouring Kukawa, looting weapons before being driven back with the help of fighter jets, according to military and local sources.
The 17-year insurgency has killed tens of thousands of people and displaced around two million from their homes in northeastern Nigeria, according to the United Nations.