Five Nigerian soldiers were killed, four injured and dozens missing when IS-aligned jihadists attacked a military base in northeast Nigeria's Borno state, two military officers told AFP Saturday.
Fighters from the Islamic State West Africa Province (ISWAP) on Friday dislodged troops from a base in Kamuya village, 35 kilometres (22 miles) from regional district Biu after a gunfight.
"The terrorists killed five soldiers and injured four others in the attack on the Kamuya base," a military officer told AFP.
The insurgents sacked the base, forcing troops to withdraw in disarray, said a second military officer, who gave the same toll.
"So far 41 troops have returned while 58 are still missing and are presumed to have escaped the attack," said the second military officer.
Search and rescue operation was ongoing to "locate the missing soldiers", the officer added.
Kamuya is the home village of Nigeria's former army chief Lieutenant-General Tukur Buratai which has been repeatedly targeted by jihadists, prompting the setting up of a base to end the attacks.
ISWAP has focused on targeting military installations and troops since it split from mainstream Boko Haram in 2016 and rose to become a dominant group.
More than 20 people were killed following days of attacks on the town of Damasak this week where the militants burnt offices of international aid agencies and several homes.
The attacks have forced 65,000 residents to flee into neighbouring Niger, according to the UN.
The 12-year jihadist conflict has killed 36,000 people and displaced around two million from their homes in Nigeria's northeast.
The violence has spread to neighbouring Niger, Chad and Cameroon, prompting a regional military coalition to fight the insurgents.