Updated

Nigeria's president has emerged to attend Friday prayers after missing a number of public engagements because of poor health.

President Muhammadu Buhari disappeared for six weeks of medical leave in London earlier this year, leading some to call for his replacement. The 74-year-old returned to work in March but has missed three straight weekly cabinet meetings.

The uncertainty over his health has raised fears of instability in Africa's most populous nation and one of its top oil producers.

Nigeria's government tweeted images of Buhari's appearance Friday as officials seek to calm the concerns.

Buhari's ailment is not publicly known, but he has made reference to blood transfusions and said he had not been so sick in decades.

His wife has said his health is not as bad as perceived.