Nigeria Boko Haram
Victims receive treatment at a hospital, after an explosion in Maiduguri, Nigeria, Wednesday, June 17, 2015. A large sack of home-made bombs discovered at an abandoned Boko Haram camp exploded, killing 63 people, witnesses said Wednesday of a toll many times higher than in any recent attack in northeast Nigeria. The explosives were found by civilian self-defense fighters who carried the bag filled with metal objects to the nearby town of Monguno, said fighters including Haruna Bukar. (AP Photo/Jossy Ola)

BAUCHI, Nigeria (AP) — A sack of home-made bombs discovered at an abandoned Boko Haram camp exploded, killing 63 people in northeast Nigeria, civilian self-defense fighters said Wednesday.

Haruna Bukar, a witness to the blast, said the local militia was patrolling the area when they discovered the camp and found the bag of metal objects, which they carried to the nearby town of Monguno.

As residents gathered around to examine the bag, it exploded, said Bukar.

Scores of people have been killed this month in suicide and other bombings carried out by Nigeria’s homegrown extremists using these kinds of improvised explosive devices.

Nigeria Boko Haram
A man inspects the site of a suicide bomb attack at a market in Maiduguri , Nigeria, Tuesday, June 2, 2015. Boko Haram attacked the northeastern Nigerian city of Maiduguri on Tuesday with deafening explosions from the west and a suicide bombing near the center that witnesses said killed as many as 20 people. (AP Photo/Jossy Ola)

Boko Haram took control of a large swath of northeast Nigeria until a multinational force this year forced them out of towns and villages. Nigeria’s military says the extremists are now confined to the Sambisa Forest.

Boko Haram denies this and has stepped up bombings and hit-and-run attacks since President Muhammadu Buhari announced at his May 29 inauguration that the command control center for the war against the insurgents is moving to Maiduguri, the biggest city in northeast Nigeria and the birthplace of Boko Haram.

The 6-year-old Islamic uprising is blamed for the deaths of some 13,000 people. More than 1.5 million have been driven from their homes, some across borders.