NAIROBI, Kenya (AP) — Police in Burundi say they have killed 22 “evil-doers” near the country’s economic capital, Bujumbura.

Police spokesman Pierre Nkurikiye asserted to reporters Tuesday that the group “took advantage of the electoral period” to cause trouble. A teacher who led the group was among those killed in the week-long operation in the districts of Isale and Nyabiraba, he said.

Local sources, however, told The Associated Press that at least 12 people were executed Sunday in Nyabiraba after being arrested by police and the ruling party youth group known as the Imbonerakure. They spoke on condition of anonymity out of concern for their safety.

The East African nation will hold a presidential election in May. The previous election in 2015 was surrounded by deadly unrest as some protested the president’s ultimately successful pursuit of another term. This time, President Pierre Nkurunziza has said he will not run.