Witnesses said at least 100 people died on Saturday (Dec. 10) in the southern city of Uyo when the Reigners Bible Church, which was still under construction, caved in during church service being held to ordain its founder as bishop.

“Until severe sanctions are meted on those who are responsible, they may not be able to stop their satanic antics,” Musa Asake, secretary of the Christian Association of Nigeria, CAN, said in a statement on Tuesday.

“It is no more news that buildings often collapse in the country as a result of contractors using sub-standard materials coupled with lack of building approvals or a thorough supervision by the relevant agencies,”

In September 2014, 115 people were killed when a guest house at the Synagogue Church of All Nations collapsed in the country’s commercial capital, Lagos.

Authorities are promising a high-level investigation into the collapse in Uyo, although no arrests had been made.

Police put the official death toll at 31, after reporting on Tuesday that two more people died of injuries.

“We have completed the evacuations and investigations are ongoing,” Cordelia Nwawe, state policewoman for coastal state of Akwa Ibom told RNS, declining to give further details.

Nigeria’s emergency management agency, NEMA, said 115 people were injured.

Nigerian authorities routinely understate casualty figures in mass accidents as well as terrorist attacks.

In Uyo, which is the capital of Akwa Ibom state, authorities appeared to be trying to protect the church’s founder, Akan Weeks. Weeks, who was among the injured, is a popular figure in Akwa Ibom, and a friend to several senior officials.

State governor Udom Emmanuel, who was at the event and escaped unhurt, said a “high-powered panel of inquiry” would be named to determine the cause of the collapse and to “bring to book persons found to have compromised professional standards in the construction of the building.”

Emmanuel said he had flown in surgeons from other parts of the country to help in treating the injured.

Building collapses are relatively common in the west African nation. Critics blame the violation of building regulations and use of sub-standard materials.

On Tuesday, the Standards Organization of Nigeria said it was investigating the incident in Uyo. Officials from the body, led by Akwa Ibom state coordinator, Dauda Mshelia, visited the site of the collapsed church building and took samples for laboratory analysis.

The Nigerian Society of Engineers also announced it was conducting an investigation.

The Christian body, CAN, advised churches to avoid holding worship service inside a building under construction to avoid a repeat of the tragedy.