The highly contagious infection can cause breathing difficulties and heart problems that can be fatal, particularly in children.

The Nigeria Centre for Disease Control and Prevention (NCDC) said there had been multiple outbreaks across the country since late last year, with almost 800 confirmed cases and at least 80 deaths.

It said the vast majority of cases were among people who had not been vaccinated - despite diphtheria being covered by the country's routine childhood immunisation programme.

The NCDC has urged the public to remain vigilant and ensure that people with symptoms to report early to health facilities for prompt diagnosis and treatment.