Nigerian President Muhammadu Buhari returned to the country on August 19, after three months in London for medical treatment.

Officials refused to disclose what the president was being treated for.

It was Muhammadu Buhari’s second spell of medical leave this year – leading many Nigerians to question whether he was well enough to run the country.

Muhammadu Buhari, 74, walked unaided from the plane after landing in capital Abuja.

The president was greeted by Vice President Yemi Osinbajo, who has acted as interim leader, and was accorded a military salute.

He made no statement and immediately traveled to the presidential residence.

Muhammadu Buhari Admits Plagiarizing Barack Obama’s Speech

Nigeria elections 2015: Goodluck Jonathan faces strong challenge from Muhammadu Buhari

Muhammadu Buhari, who took office in May 2015, handed over power to Vice President Osinbajo to allay concerns of a void at the helm of Africa’s biggest economy.

The president’s absence sparked numerous protests, including demands that he should resign, as well as calls for more transparency about his condition.

There has been speculation about Muhammadu Buhari’s health since June 2016, when he first went to London for treatment of what his aides said was a persistent ear infection.

Muhammadu Buhari’s spokesman said he will address Nigerians on August 21.