It was learnt that the bag laden with explosive was abandoned by Boko Haram.
According to reports, the Vigilante members had earlier engaged the sect members in a fight during which they chased them out of their community.
While trying to escape, the sect members abandoned their weapons, which included guns and other objects, one of which was a booby trap.
Haruna Bukar, an operative of the Vigilante Group of Nigeria (VGN), who claimed to have witnessed the incident informed journalists on phone that a group of Civilian-JTF members discovered a heavy bag filled with explosives at an old camp of the Boko Haram sect along Monguno-Marte road, and decided to bring it into the city.
“It was not an attack by Boko Haram, but explosion from a discovered bag filled with bombs”, he said.
“When they found the bag containing what later turned out to be improvised explosives, they brought it to Monguno town where people gathered to take a look at it. As they were busy fiddling with the content of the bag, the bombs went off with a massive blast that killed about 63 persons and injured dozen others”.
Many of the onlookers and by-passers were also injured by the blast that occurred at about 5 pm.
62 bodies have been evacuated from a trailer that is being used to remove the bodies from the scene of the incident to the State Special Hospital morgue in Maiduguri.
The federal government is fighting a 6-year battle with Boko haram terrorists, which has killed over 200 people since President Muhammadu Buhari took over from Goodluck Jonathan on May 29, 2015.
Meanwhile, President Buhari has vowed to rid Nigeria of Boko Haram insurgents. He, in collaboration with Neighbouring Niger, Chad and Benin Republic, have resolved to form a Multinational Joint Task Force to fight Boko Haram.
The President has also moved the command centre of the Nigerian Army to Maiduguri, near the hotbed of Boko haram insurgency to boost proper coordination of military activities.