Fighters from the Islamic State West Africa Province faction of Boko Haram attacked a military base in Gudumbali late on Friday, December 14, military sources told AFP.

Fighters in several technicals – trucks fitted with anti-aircraft guns – attacked the base around 7:00 pm (1600 GMT), leading to an hours-long fight, the two military sources said.

The attack was repelled with aerial support, the sources said.

There were no reports of casualties.

Update Sunday, December 16 Islamic State claimed fighters from its West Africa Province affiliate attacked a military barracks in Gudumbali, killing five soldiers and injuring others. ISIS claimed two “tanks” and two other vehicles were destroyed, while militants captured three four-wheel-drive vehicles, weapons and ammunition.

The Nigerian Army on Sunday said it repelled an attack on Gudumbali on Friday. One soldier was killed and another wounded in the firefight.

Colonel Onyema Nwachukwu said in a statement that troops “repelled an infiltration by suspected Boko Haram terrorists that came disguised as civilian Internally Displaced Persons.”

Nwachukwu said the militants “took advantage of the ongoing distribution of relief materials” the army and opened fire on troops. This was followed by fire “from other terrorists in gun trucks along Gudumbali-Kukawa axis.”

Trucks carrying humanitarian aid were set on fire, and a Cobra Armoured Personnel Carrier and a military truck were also damaged.

Troops “inflicted heavy casualties” on the attackers and recovered bodies, Nwachukwu said but did not specify how many. A “large quantity of ammunition” and eight rocket propelled grenades were also recovered.

Three military sources told Reuters on Sunday that at least 12 Nigerian soldiers were killed and dozens of others were missing after the attack on a military base and a nearby community in Gudumbali local government area. One source said 28 militants were killed.

The town of Gudumbali in Guzamala district of Borno state has been attacked several times in recent months.

On December 4, ISWAP fighters attacked a military base in Gudumbali, sparking a fierce firefight in which two soldiers were injured, while in early September, thousands of civilians were forced to flee after Boko Haram militants took control of the town before withdrawing the following day.

Surge in Boko Haram attacks

Boko Haram split into two factions in mid-2016 over ideological differences. One is led by Abu Mus’ab Al-Barnawi and largely focuses on attacking military and government targets, while the other, led by Abubakar Shekau, is notorious for suicide bombings and indiscriminate killings of civilians.

Shekau has pledged allegiance to ISIS leader Abu Bakr Al-Baghdadi, but ISIS central gave its formal backing to the Barnawi faction, which is known as Islamic State West Africa Province.

ISWAP has lately intensified its armed campaign, launching a number of major assaults on military targets in Borno and neighbouring Yobe state amid signs of a takeover by more hardline leaders.

There have been more than 20 attacks on military bases since July, with at least nine so far this month. Most of the attacks have been blamed on ISWAP, or claimed as ISWAP attacks by ISIS.

On December 14, Nigerian soldiers were killed in roadside bomb blast near Gamboru.

Boko Haram fighters attacked a military base in Gulumba killing at least two soldiers on December 8. The attack involved a suicide bomber, a hallmark of the Shekau faction.

Three civilians were killed in fighting between troops and ISWAP in Jakana on December 7.

Two military bases were attacked in the Rann and Bama areas of Borno on December 6 and 7.

On December 4, ISWAP fighters launched an assault on a military base in Gudumbali, sparking a fierce firefight in which two soldiers were injured.

ISWAP fighters attacked a military base in Mallam Fatori near the borders with Niger and Chad on December 3. One soldier was killed and several others were injured in the attack.

On December 1, an ISWAP attack in the Yobe state village of Buni Gari left eight soldiers dead, the Nigerian army said, while ISIS claimed ISWAP fighters killed 17 soldiers.

Also on December 1, ISIS claimed ISWAP killed eight Nigerian soldiers and wounded 17 others in an attack near Gamboru. The Nigerian Army said that it captured weapons and stores during “offensive patrols” in the area, but did not mention army casualties.

The military on November 30 lashed out at the media, saying some media outlets were “creating erroneous impression of the Nigerian Army through inaccurate and false publication of casualty figures.”

The military has even threatened legal action against organisations publishing unofficial figures.

On December 14, the military briefly banned the United Nations children’s agency UNICEF from operatiing in northeastern Nigeria. The military claimed UNICEF was training spies to sabotage counter-terrorism and counter-insurgency efforts. The suspension was lifted several hours later.

Borno and Yobe states, along with nearby Adamawa state, have born the brunt of nine years of jihadist violence that has claimed 27,000 lives and forced 1.8 million people to flee their homes.

The recent surge in Boko Haram attacks has increased pressure on President Muhammadu Buhari, who was elected in 2015 on a promise to defeat the Islamists and has repeatedly said they are virtually defeated. His administration wants to show it is winning the fight against Boko Haram ahead of a presidential election in February at which he will seek a second term in office.

With reporting from AFP