Nigerian terrorist group Boko Haram has released a video depicting their slaughter of captive civilians. Despite this new footage of brutality, the group has suffered some losses across Nigeria's borders.

The video, in which Boko Haram's flag can be seen, shows fighters from the Islamic extremist group shooting unarmed captives and declaring they will no longer keep prisoners, The Associated Press reports. 

Boko Haram released the 10-minute long video to the media, and it shows fighters from the terrorist group shooting prisoners with AK-47s inside a dormitory, according to Bloomberg.

One of the fighters, who is the leader of the band, spoke Arabic, Hausa and Kanuri and said they were in Bama in the northern Borno state.

"Even though the prophet had advised during his time that prisoners can only be kept and not killed, we felt this is not the right time for us to keep prisoners," the unidentified Boko Haram fighter said. "We have made sure the floor of this hall is turned red with blood, and this is how it is going to be in all future attacks and arrests of infidels."

Most of the victims appear to be adult men deemed to be "infidels" by the religious extremist group.

"From now, killing, slaughtering, destructions and bombing will be our religious duty anywhere we invade," the fighter said.

Bama, where the massacre took place, is close to Gwoza, a town Boko Haram attacked on Thursday.

However, the Sunni extremist group's reach has expanded past Nigeria's borders, where the conflict began in 2009. Boko Haram has conducted attacks in Niger, Cameroon and Chad, AP reports.

The attacks on towns across Nigeria's borders have worsened the humanitarian crisis and expanded it into the region. Yet, Nigeria's neighbors have begun acting. Chad has started a counterterrorism unit, and Cameroon has begun counterattacks against Boko Haram.

Cameroon's latest attack on Saturday dismantled a Boko Haram training camp in the town of Guirvidig near the Nigerian border, reports Reuters. The Cameroon army "seized 84 children between seven and 15 who were undergoing training in the camp, arrested 45 of the trainers and killed many more," according to a Cameroon's Ministry of Defence spokesperson.