A Kenyan court on Wednesday denied bail for cult leader Paul Mackenzie, who authorities say ordered followers to starve their children and themselves to death, and extended his detention by 30 days.

The death toll climbed to 145from 133 announced on Tuesday, and hundreds of people are still missing. Authorities are searching for remains in shallow graves scattered throughout a forest where Mackenzie's followers were living.

Mackenzie, leader of the Good News International Church, has not yet been required to enter a plea after handing himself over to police last month. A lawyer representing Mackenzie, George Kariuki, has said the self-styled pastor is cooperating with the investigation.

Magistrate Yusuf Shikanda said at a hearing in the port city of Mombasa that Mackenzie and 17 other people detained in connection with the deaths would not be granted bail because of concerns that their release would jeopardise investigations.

Wycliffe Makasembo, a lawyer for Mackenzie and his wife, who is also detained, said he would appeal against the decision.

"The ruling was not within the law. It violates the constitutional rights of our clients," Makasembo told Reuters.

Mackenzie was arrested earlier this year on suspicion of the murder of two children by starvation and suffocation, but was then released on bail.

Relatives of his adherents say that after he was freed, he returned to Shakahola forest and brought forward his predicted date for the end of the world from August to April 15.

Mackenzie surrendered to police on April 14 after police first raided the forest where the church was based, rescuing 15 people who had been starving themselves.