President Muhammadu Buhari starts his second four-year tenure as the country battles severe security challenges.
Nigerian President Muhammadu Buhari was sworn in for a second four-year term in power on Wednesday, promising again to tackle crippling security threats and end rampant corruption in Africa's key economy.
"I do solemnly swear that I will be faithful and bear true allegiance to the Federal Republic of Nigeria," Buhari said, dressed in simple white robes and traditional embroidered cap. "I will preserve, protect and defend the constitution."
Under tight security
The low-key ceremony is taking place in the capital Abuja while newly-elected governors are being sworn into office in state capitals.
Concern about extremist attacks, however, have prompted authorities in Buhari's home state of Katsina in the north to cancel the inauguration of its governor.
Buhari has remained relentless in assuring Nigerians of four years of peace despite a spike in attacks in northern Nigeria this year.
This has left the military overstretched and seen Buhari criticised for failing to protect lives and property.
Journalist Cynthia Agbor reports from Nigeria's capital Abuja.
The 76-year-old Buhari won February's election despite frustration with what many people have called a slow, insufficient approach to tackling corruption, insecurity and the economy.
During his first term, Buhari faced serious questions about his health. He spent more than 150 days outside the country for unspecified medical treatment.