At least 160 people are feared dead and scores more injured after metal girders and the roof of a crowded church collapsed onto worshippers in southern Nigeria, said a report.

Mortuaries in the city of Uyo are overflowing from Saturday's tragedy, said medical director Etete Peters of the University of Uyo Teaching Hospital, according to an AP report, citing the hospital director of the area.

The Reigners Bible Church International was still under construction and workers had been rushing to finish it in time for Saturday's ceremony to ordain founder Akan Weeks as a bishop.

Screaming survivors were streaming out and there were cries from injured victims when computer program analyst Ukeme Eyibio rushed to the scene.

"There were trapped bodies, parts of bodies, blood all over the place and people's handbags and shoes scattered," Eyibio said.

He had parked his car outside the complex to make a phone call, heard a deafening explosion he thought was a bomb only to see that the church had disappeared, he said.

Eyibio and three others managed to drag 10 wounded people from an overflow area for worshippers just outside the collapsed church but they did not enter the main structure because a construction worker among them warned of the danger of a further collapse.

Journalists at the scene claim that church officials were trying to prevent them from documenting the tragedy, trying to seize cameras and forcing some to leave the area.

The governor's spokesman, Ekerete Udoh, said the state government will hold an inquiry to investigate if anyone compromised building standards.

Buildings collapse often in Nigeria because of endemic corruption with contractors using sub-standard materials and bribing inspectors to ignore shoddy work or a lack of building permits.