Amnesty report: 381 civilians have been killed by Boko Haram since April

At least 381 civilians have been killed in attacks carried out by Boko Haram militants in Nigeria and Cameroon since April, according to a report by Amnesty International.

Although the Nigerian military has repeatedly declared that Boko Haram has been "defeated," the insurgent group has carried out a series of deadly attacks in Nigeria and Cameroon in recent months.

According to Amnesty International, the number of casualties resulting from the resurgence of attacks has more than doubled compared to the previous five months.

"Boko Haram is once again committing war crimes on a huge scale, exemplified by the depravity of forcing young girls to carry explosives with the sole intention of killing as many people as they possibly can," said Alioune Tine, Amnesty's director for West and Central Africa.

At least 223 civilians have been killed in Nigeria since April, but the human rights group said that the real toll could be higher.

In July, Boko Haram reportedly abducted an oil exploration team with staff of the state oil firm and of a university while they were traveling in a military convoy. Forty people were killed by the militants and three others were kidnapped.

"Between May and August, seven times more civilians were killed than in the preceding four months, while 100 civilians were killed in August alone," the NGO said in its report, according to Al Jazeera.

In neighboring Cameroon, as many as 158 civilians have died in attacks carried out by Boko Haram since April.

"The recent spike in casualties has been driven by increased suicide attacks, with 30 - more than one per week - carried out since the beginning of April," the report noted.

The deadliest attack in Cameroon took place in the town of Waza on July 12, when a young girl detonated a bomb in a crowded video game center, killing 16 civilians and injuring 34 others.

In late August, UNICEF reported that at least 83 children have been used by the terror group as "human bombs." As many as 55 children were girls, often under 15 years old. Twenty-seven of the child bombers were boys, and one was a baby strapped to a girl.

The UN agency expressed concerns that children who escaped or were released by Boko Haram come to be viewed with suspicion and rejected by their communities.

Boko Haram has killed over 20,000 people since the insurgency began in 2009. Amnesty International noted that at least 2.3 million people in the region have been displaced and 7 million are facing serious food shortages.