A wealthy Nigerian politician and his family plotted to bring a street trader from Nigeria to Britain and pay him a few thousand pounds to donate his kidney for a transplant for his ill daughter, reports say.

Nigerian military leaders say the report is an insult to Nigerians and part of a foreign effort to undermine the country's fight against the insurgents.

The violence at St Francis Catholic Church in the city of Owo during Sunday mass was a rare assault in a region usually considered safer than others in the country, and drew widespread international condemnation.

Muslim youths took to the streets of the city, lighting bonfires and demanding the release of the two detained suspects.

Dozens of Muslim students went on rampage after a fellow student, Deborah Samuel, made a statement on social media which they considered offensive against the Prophet Muhammad, according to local police.

Since Boko Haram jihadists kidnapped more than 200 schoolgirls from the northeastern town of Chibok in 2014, dozens of schools have been targeted in similar mass abductions.

The airstrike occurred in a region where banditry is common and where both governments fear that Islamist insurgents linked to Islamic State are gaining ground.

In Nigeria, Africa's most populous nation and home to more than 200 million people, fewer than 4% of adults have been fully vaccinated, according to WHO.

Building collapses are frequent in Africa's most populous country, where regulations are poorly enforced and construction materials often substandard.

This is the third such major attack on prisons this year.

The conflict between the insurgents and Nigeria's armed forces, which has also spread to neighbouring Chad and Cameroon, has left about 300,000 dead and millions dependent on aid.

Assailants had stormed Bethel Baptist High School on July 5 on the outskirts of Kaduna city, abducting 121 students who were sleeping in their dorms.