Islamic militants have again attacked the remote Nigerian town from which nearly 300 schoolgirls were kidnapped.
Nigeria's military said yesterday it resulted in a firefight that killed 12 soldiers and led angry troops to fire on a commanding officer.
Soldiers said the troops fired at a senior officer who came to pay respects to the killed soldiers, whose bodies were brought to a barracks in Maiduguri, the capital of north-eastern Borno state.
It's another sign of demoralisation in the military that is in charge of the search for the abducted schoolgirls.
The failure of Nigeria's government and military to find them after the April 15 mass abduction has triggered national and international outrage and forced Nigeria's government to accept international help last week.
Nigeria's ministry of defence played down yesterday's shooting incident, saying soldiers "registered their anger about the incident by firing into the air - the situation has since been brought under control".
It happened in Maiduguri, about 80 miles north of Chibok, where the girls were abducted.
But soldiers who were at the scene at Mailamari Barracks said infuriated troopers fired directly at the vehicle carrying Major General Ahmadu Mohammed, the general officer commanding the army's 7 Division. He was not hit.
The witnesses said the soldiers were angry because they wanted to spend the night in a village and told their command the road was dangerous after the attack around Chibok.
They were ordered to travel instead and were ambushed, with at least 12 killed.
The ministry of defence, which often exaggerates the number of enemy killed and downplays its own losses, said four soldiers were killed along with several insurgents.
"Troops engaged the insurgents in a fierce combat and extricated themselves from the ambush killing several insurgents. Four soldiers however lost their lives during the ambush," said a statement from the ministry spokesman, Major General Chris Olukolade.
There is growing anger at the military's failures, though soldiers have told The Associated Press that they are outgunned and outnumbered by the insurgents, do not have bullet-proof vests, are not properly paid and have to forage for food.
A sign of their failure is the vigilante groups to fight the extremists that have been springing up in north-east Nigeria over the past year.
In Kalabalge, a village about 155 miles from Maiduguri, residents took matters into their own hands.
On Tuesday morning, after learning about an impending attack, villagers ambushed two trucks with gunmen.
At least 10 suspected militants were detained, and scores were killed, one official said. It was not immediately clear where the detainees were being held.
Kalabalge trader Ajid Musa said that after residents organised the vigilante group "it is impossible" for militants to successfully stage attacks there.
Earlier this year in other parts of Borno, extremists launched more attacks in retaliation over the vigilante groups.
Borno is one of three Nigerian states where President Goodluck Jonathan has imposed a state of emergency, giving the military special powers to fight the Islamic extremist group, whose stronghold is in Maiduguri.
Britain and the US are now actively involved in the effort to rescue the missing schoolgirls.
US Attorney General Eric Holder said FBI agents and a hostage negotiating team are in Nigeria now, providing technology and other materials and working with "our Nigerian counterparts to be as helpful as we possibly can".
US reconnaissance aircraft are flying over Nigeria in search of the missing girls.
At least 276 of the schoolgirls are still held captive, with the group's leader threatening to sell them into slavery. In a video released on Monday, he offered to release the girls in exchange for the freedom of jailed Boko Haram members.