BAMAKO, Mali (AP) — A humanitarian crisis is worsening in northeastern Mali where armed groups linked to Islamic State have besieged major towns leaving residents including some 80,000 children vulnerable to malnutrition, locals and an aid group warned Wednesday.

The town of Ménaka has been under siege for four months, driving up the prices of food. Other essential goods like medication are increasingly hard to find, residents and aid groups say.

“The humanitarian situation is catastrophic, with displaced people going from house to house asking for food for their families. Children are threatened with starvation,” Wani Ould Hamadi, deputy mayor of the town of Ménaka, told the Associated Press.

Mali, along with its neighbors Burkina Faso and Niger, has for over a decade battled an insurgency fought by armed groups, including some allied with al-Qaida and the Islamic State group. Following military coups in all three nations in recent years, the ruling juntas have expelled French forces and turned to Russia’s mercenary units for security assistance instead.