Former military ruler Muhammadu Buhari has formally been sworn in as Nigeria’s next president after he defeated President Goodluck Jonathan in March 28 elections.

Buhari, who was sworn-in in the captial city of Abuja on Friday, is the first Nigerian to oust a sitting president through the ballot box.

Dressed in traditional Muslim attire, Buhari stood on the stage clutching a Koran in his right hand, as he pledged to uphold the constitution and laws of Africa’s most populous nation.

The 72-year-old, takes over as head of Africa’s most populous nation, top economy and leading oil producer as it limps back to normality after fuel shortages that brought the country to a near standstill.

A sandal-wearing ascetic from Nigeria’s predominantly Muslim north, Buhari has already pledged to get tough on the corruption that pervades every aspect of life the country.

Buhari has vowed to spare no effort to defeat the Boko Haram armed group which has killed thousands and displaced more than a million people in a six-year campaign to establish a caliphate in the northeast region abutting Lake Chad.

About 30 countries have sent high-level representatives for the ceremony, many from the rest of the African continent, which stands to gain if Buhari is able to breathe new life into the economy and restore Abuja’s diplomatic credibility and clout.

Muhammadu Buhari and Goodluck Jonathan

Muhammadu Buhari and Goodluck Jonathan

South African President Jacob Zuma attended the ceremony – a sign of Pretoria’s desire to improve relations with Abuja after a series of diplomatic spats under Jonathan, including the deaths of 84 South Africans in a Lagos church building collapse in September, and a wave of attacks on foreigners in South Africa this year.

US Secretary of State John Kerry, British foreign secretary Philip Hammond and French foreign minister Laurent Fabius were also at the event.

Roads were closed around the Eagle Square inauguration venue, where dozens of international flags have been hoisted alongside the Nigerian green and white triband and soldiers patrolled.

The venue was surrounded by barbed wire and giant posters of Buhari had been hung, alongside vice-president-elect Osinbajo, as workers rolled out red carpets and arranged flowers.

On the streets, traders were gearing up for Friday’s event, selling watches, badges, hats and green and white polo shirts emblazoned with his campaign slogan “Sai Buhari” (Only Buhari).

Al Jazeera’s Yvonne Ndege, reporting from the ceremony, said that people in the country feel like he will rule differently, and have a lot of confidence that he’d be able to take on many of the challenges.

“The hope is that once the ceremony is over, the hard work of governance and putting hope in Nigeria will begin.”

Source: Al Jazeera and agencies