As many as 60% of the “mysterious” deaths in Nigeria’s northern Kano state were likely due to the new coronavirus, the government’s health minister said on Monday.

Nigeria’s task force on COVID-19 sent a team to the northern economic hub in late April to investigate and conduct “verbal autopsies” after local newspaper the Daily Trust reported a spike in deaths to around 150 people in Kano city.

Government Minister of Health Osagie Ehanire said the investigation found a total of 979 deaths were recorded in eight municipal local government areas in Kano state at a rate of 43 deaths per day, compared with the typical death rate of roughly 11 deaths per day.

“With circumstantial evidence as all to go by, investigation suggests that between 50-60% of the deaths may have been triggered by or due to COVID-19, in the face of pre-existing ailments,” Ehanire said.

He said the peak in deaths occurred in the second week of April, and that by the beginning of May, the death rate had gone back down to the normal rate.

The Kano state government had said the deaths were caused by complications from hypertension, diabetes, meningitis and acute malaria and not the COVID-19 pandemic.

Kano state entered a lockdown in April to stem the spread of the virus. The federal government said this month it would ease the lockdown.

Nigeria currently has 12,486 confirmed coronavirus cases, 999 of them in Kano, and a total of 354 deaths. Just 48 of the officially confirmed deaths due to COVID are in Kano state.