Hundreds of people are suspected to have been killed in the attack, which took place earlier in the week. At least 200 people had died, although some community leaders put the death toll at between 400 and 500. There is not yet independent verification because of the lack of communication in the remote area. Roads out of the region are extremely dangerous and phone connections are poor to nonexistent.
The militants arrived in Toyota Hilux pickup trucks - a common vehicle for the military - and told civilians they were soldiers there to protect the local population. Local residents had requested military help. The same tactic was used by Boko Haram to kidnap more than 300 schoolgirls from the town of Chibok on April 15.
The gunmen reportedly gathered people in the center of the villages and fired on them. As people attempted to flee, militants on motorcycles waited outside the villages and attack them.
Mohammed Ali Ndume, a senator representing Borno and whose hometown is Gwoza, confirmed the attack. Peter Biye, who represents Gwoza in Nigeria's lower chamber of parliament the House of Representatives, said that the militants still had control of the area.
"The killings are massive but nobody can give a toll for now because nobody has been able to go to that place because the insurgents are still there. They have taken over the whole area," he told the AFP news agency. "There are bodies littered over the whole area and people have fled."
Boko Haram militants have been taking over villages in northeastern Nigeria as the group fights back against the year-long military campaign to defeat them. If confirmed, Monday's attacks would be the deadliest since more than 300 people were killed on May 5 when militant fighters raided the nearby town of Gamboru Ngala.
Thousands of people have been killed in Boko Haram's five-year insurgency, and more than 2,000 just this year alone. An estimated 750,000 Nigerians have been forced to flee their homes due to the violence.
Since the schoolgirls' abduction by Boko Haram militants in April, Nigeria's government has been widely criticized for its failure to locate and rescue them.
Earlier this week, police banned protests because they were said to be a threat to national security. Protests have since resumed across the country.