Abuja (AFP) - Dozens of soldiers were feared dead after a Boko Haram attack on a military base in remote northeast Nigeria, security sources said on Monday, as search parties were sent into the bush to locate missing troops.
Jihadists overran the base in Jilli village, in the Geidam area of Yobe state, on Saturday evening, a day after a separate attack on troops in neighbouring Borno state.
The army conceded the base was attacked but said "troops reorganised and successfully repelled the attack and normalcy has since returned to the area".
But one military source told AFP earlier: "So far we have lost 31 soldiers, including three officers.
"Two vigilantes were also killed in the attack," he said, adding that 24 soldiers were injured and were being treated in hospital.
A civilian militia source in the Borno state capital, Maiduguri, added: "I don't have an exact toll of those killed.
"But yesterday (Sunday) the dead casualties were brought in three trucks to Maimalari military barracks here in Maiduguri. This means the casualty toll is high."
- Operational mistake -
The militia member said Boko Haram fighters in military uniform and driving vehicles painted in army colours were allowed into the base.
"The soldiers mistook them for their colleagues from Gubio and opened the gates to the base. This was what led to all this loss," he added.
More than 700 soldiers were at the base at the time and hundreds of them were unaccounted for as of Sunday.
But army spokesman Brigadier General Texas Chukwu said reports that 600 soldiers were missing were "untrue".
"All the troops in the base were accounted for," he added in a statement.
The military source, who asked to remain anonymous because he was not authorised to talk to the media, said "a number of the missing soldiers have showed up".
He did not specify a figure.
Reinforcements have now been sent to the base while commanders have sent search parties into the bush to locate any soldiers killed, missing or wounded in action.
The attack is suspected to have been carried out by fighters loyal to factional leader Abu Mus'ab al-Barnawi, who is backed by the Islamic State group.
The group has previously attacked government and military targets.
In the latest strike, the military base commander had to crawl to safety after troops tried to fight back but were overwhelmed.
A number of army vehicles were burnt or taken away, while the insurgents also stole arms and ammunition, burnt down food and uniform stores and a church worship centre.
There was no exact figure on Boko Haram casualties but many were said to have been killed.
- Ambush -
Meanwhile, a search and rescue operation was understood to be ongoing in the Bama area of Borno state for 18 soldiers and five officers missing since Friday's attack.
Local security operatives said seasonal rains were hampering the search.
Chukwu again dismissed reports of missing troops and said the attack was "successfully repelled". Twenty-two jihadists were killed and one soldier was injured, he added.
At least 20,000 people have been killed in Boko Haram violence and more than two million others made homeless in northeast Nigeria since 2009.
The government and military have repeatedly maintained Boko Haram is now a spent force and either weakened to the point of defeat or even defeated.
President Muhammadu Buhari indicated last week the conflict was over and northeast Nigeria was now in a "post-conflict stabilisation phase".
But raids on military bases, attacks on security checkpoints and suicide attacks continue, with troops, militia and civilians still vulnerable.
International aid agencies working in the region say insecurity in hard-to-reach rural areas means they are unable to help people in desperate need.