Kenyan police began exhuming bones from more than a dozen suspected graves in the country’s east on Friday, believed to include members of a Christian sect who believed starving themselves to death would get them into paradise.

According to Citizen TV footage, homicide investigators marked off portions of dirt with sticks and yellow tape on Thursday in Shakahola woodland in Kilifi county, near the spot where police rescued 15 members of the Good News International Church last week.

Police began exhuming bodies on Friday, said Charles Kamau, a detective in the nearby town of Malindi, without giving further details.

The leader of the church, Paul Mackenzie, was arrested following a tip-off that also suggested the existence of shallow graves belonging to at least 31 of Mackenzie’s followers.

Mackenzie’s lawyer could not immediately be reached for comment.

Police said the 15 rescued worshippers had been told to starve themselves to death so they could meet their creator. Four of them died before they reached hospital.

Titus Katana, a former member of the church, helped police identify the graves.

“We have shown the graves to the police, and in addition, we have saved the life of a woman who only had a few hours left, otherwise she’d also be dead,” Katana told Citizen TV.

Matthew Shipeta from Haki Africa, a human rights group, said he had seen at least 15 shallow graves in the forest.

Helen Mikali, the manager of a children’s home who was also helping investigators, said she had visited several nearby villages where parents and children had disappeared.

“Personally I have visited about 18 children’s graves,” Mikali told Citizen TV. She did not say how she knew the graves contained the remains of children.

Last month police arrested and later released Mackenzie, who they identified as Paul Nthenge Mackenzie, for encouraging the parents of two boys to starve and suffocate their children to death.

During a court appearance in that case, Nthenge said he was unaware of the events that led to the deaths of the two boys, adding he was the target of hostile propaganda from some of his former colleagues, The Standard newspaper reported.