The ambush, according to military officials briefed on the matter, occurred at about 2:30 p.m. Saturday between Jagiran and Monguno, one of the hotspot of the decade-long Boko Haram insurgency in Borno State.
The terrorists also carted away a Toyota bullet-proof Land Cruiser SUV with desert camouflage colour, belonging to the acting commander of the 3rd Armoured Division.
Army authorities fear that the vehicle could be repainted with disguise in order to gain entry into military bases.
To that end, the army has also placed the Nigerian troops in the different locations on red alert, urging them to scuttle further escalation of trouble from the terrorists if they sniff any. The police have also been notified to look out for the SUV across the country, a military source said.
The police were urged to use tact should they spot an SUV approaching their location either with mounted with a gun or not.
A spokesman of the army, Sagir Musa, did not return calls and a text message sent to him Sunday evening.