The death toll in last week's collapse of a guesthouse at a church run by a famous Nigerian preacher has risen to at least 70, a rescue agency official said Wednesday.

Rescuers have helped 131 other people out of the rubble and still are looking for more survivors from Friday's collapse of the two-story guesthouse at The Synagogue, Church Of All Nations, Nigerian Emergency Management Agency spokesman Ibrahim Farinloye told reporters at the collapse site.

The building, at the church run by televangelist T.B. Joshua in the Ikotun area of Lagos, came down Friday afternoon amid work to build additional floors, NEMA said.

Farinloye said NEMA hasn't identified the victims. On Tuesday, South African President Jacob Zuma said 67 South Africans were among the dead.

"This is a particularly difficult time for South Africa. Not in the recent history of our country have we had this large number of our people die in one incident outside the country," he said, according to a statement released by the President's office Tuesday.

NEMA said an investigation into the cause hasn't begun. But on its Facebook page Friday, NEMA said that two stories were being added without fortifying the foundation of the initial structure, and that there was a "high probability" this is what led to the collapse.

Joshua, dubbed "The Prophet" for his self-acclaimed healing powers and prophesies, has a large following among Nigerians and followers across the world.

His church attracts thousands of followers who attend every week to listen to his sermons, which are also telecast live on the church's television station.

"People travel from around the world to witness and receive from the mighty work that God is doing in the life of Prophet TB Joshua," the church's website says.