Nigeria held a state funeral for dozens of worshippers killed by gunmen at a church service earlier this month as authorities were pressed to take swift action to avoid future massacres.

Mourners paid their respects on Friday to 22 victims killed at the St Francis Catholic Church in southwestern Ondo state on June 5. Family members earlier held funerals for the other 18 victims.

The sight of their coffins, dotted with flowers and lined in front of a large crowd, drew anger and tears from church members, locals, officials and many Nigerians who followed the service on social media.

One of the coffins had a pair of policeman’s boots placed on top for the officer who was killed.

"We have failed to defend these people – not because we are not trying but because the forces on the other side are evil and they have support,” said Ondo State Governor Rotimi Akeredolu.

Survivors said the attackers bombarded the church-goers with bullets during a 30-minute-long attack. Five children were among the dead.

‘Glaring weakness’

No one has claimed responsibility for the church killings and authorities have yet to announce any arrests in connection with the attack.

Last week, the Nigerian security council said it suspected the attackers had links to Islamic State West Africa Province, an offshoot of the Boko Haram armed group which has waged a decade-long rebellion in Nigeria’s northeast.

Bishop Jude Arogundade of the Ondo Catholic Diocese accused Nigerian authorities of making "all these empty promises” to find the killers.

"This country, you don’t have shame any more. You just talk, you don’t match your talk with words,” the bishop said, urging attendees at the funeral to "claim this country back from those destroying it”.

The incident drew international condemnation, including from Pope Francis, and was a rare attack in the country’s usually safer southwest region.

The church attack also reignited calls for policing and security reforms in Nigeria, where armed violence has killed thousands during the past year. The country has also faced attacks by armed groups, as well as bandits and those who kidnap for ransom.

Bishop Emmanuel Adetoyese Badejo of the Oyo Catholic Diocese said the attack is not isolated as similar violence is "happening all over” Africa’s most populous nation.

"We call on President [Muhammadu] Buhari and our leaders in the federal and state governments to wake up, sit up, and secure lives and properties all over Nigeria,” the cleric said during the homily.

"How many more must die? Does life really have any value any more with you? Is the glaring weakness and helplessness of our security agencies ill or deliberate?” Badejo added.