YAOUNDE, Cameroon (AP) — At least 50 people were kidnapped in two separate incidents over two days in northern Cameroon, local authorities said Tuesday.

The kidnappings occurred Sunday and Monday afternoons by an unknown armed group near the border with Chad, the mayor of Touboro town, Celestin Yandal, told The Associated Press.

Seven people have been released so far. Abductions in this area happen often, but locals say the scale of these attacks is rare.

The first kidnapping took place between Touboro and Koutere towns, where mostly Chadians were taken as well as some people from Cameroon including students and shopkeepers, the mayor said.

The second abduction occurred while people were traveling on a bus from Ngaoundere city to Touboro, he said.

Cameroon has been plagued by fighting since English-speaking separatists launched a rebellion in the Central African nation in 2017 with the stated goal of breaking away from the area dominated by the French-speaking majority and setting up an independent, English-speaking state.

The government has accused the separatists of committing atrocities against civilians. The conflict has killed more than 3,300 people and displaced more than 750,000 others, according to the United Nations.

The country also faces a threat from Islamic extremists in the region.