Parents of children abducted in northeastern Nigeria have staged a protest demanding government action nearly 100 days after the students were taken, multiple outlets said on Friday. Around 40 children remain missing following the attack in Borno State.

Families gathered in Uba on Thursday to call on the federal government to secure the children’s release, Daily Trust reported. The abduction occurred on May 15 in Mussa, a settlement near the Sambisa Forest, an area that has for years been used by Islamist militant groups.

The attack occurred while classes were underway at Mussa Primary and Junior Secondary School in the Askira-Uba area. Senator Ali Ndume said at the time that school officials had told him 32 pupils were abducted from the school and another ten were seized from homes nearby. No group claimed responsibility for the attack.

Chinda Buba, whose child was abducted, told Reuters that they still had not seen their children and did not know where they were, adding that they were uncertain whether they were healthy or facing difficult conditions.

A police spokesperson said that the military was “on top of the situation” and referred further questions to the armed forces.

Boko Haram and its splinter group, Islamic State West Africa Province (ISWAP), have previously targeted schools in the northeast. The region has been at the center of a longstanding Islamist insurgency, with mass abductions, including the 2014 kidnapping of more than 270 Chibok schoolgirls.

In June, the Nigerian Army said it had rescued 360 hostages, including women and children, from a Boko Haram enclave in the state of Borno following what it described as “weeks of painstaking intelligence preparation.” According to the military, the captives were held in harsh conditions after being abducted from several communities in the region.