Authorities in Cameroon say more than 5,000 people have been freed from captivity under the Boko Haram since the end of January, and more than 60 of the extremist group’s fighters have been killed by Cameroonian and Nigerian soldiers.

Troops have also destroyed the residence of a Boko Haram leader which also served as a hideout for the extremists, along with a huge consignment of weapons, vehicles and motorcycles, he said. No soldiers have been killed, said government spokesman Issa Tchiroma Bakary, according to the Associated Press.

“At least 60 terrorists were killed, 21 suspects were arrested and are helping Cameroon and Nigerian military in their investigations,” Bakary said. “A refuge center for the insurgents is entirely destroyed on the Mandara highlands, a petroleum depot destroyed and an explosive factory destroyed.”

Those who have been freed, including elderly persons, have been transported to a camp for displaced people in the Nigerian town of Banki, where they are receiving treatment from both Cameroonian and Nigerian military health workers, Bakary said.

Boko Haram, an Islamic militant group aligned with ISIS, operates primarily in rural areas of Nigeria, is said to be responsible for the deaths of as many as 20,000 people, left 2.6 million homeless and more than 5 million refugees in urgent need of food aid.

The group is said to have been in operation since at least the 2000s, but came into global focus when 270 schoolgirls were kidnapped from their school in Chibok, located in northeastern Nigeria. In October 2016, 21 of the girls were released in a brokered deal, in exchange for four of their soldiers. Other girls have escaped from the group’s compound, but it is unclear how many have died while being held by them. The kidnapping spurred the #BringBackOurGirls movement.

In December, Nigeria’s President Muhammadu Buhari announced troops had chased Boko Haram militants out of their key remaining base in the Sambisa forest, another former stronghold that straddles Cameroon’s border with Nigeria.

Cameroon and Nigeria that same month reopened the border between the two countries for the first time in three years.

— With reporting by AP