Warning: This story contains disturbing details.

Malaysian police said Monday they have rescued 187 more children and raided locations nationwide linked to an Islamic business group that is being investigated for alleged sexual assault of children.

National police chief Razarudin Husain said the children and young people, including 59 under age five, were rescued from welfare homes linked to Global Ikhwan Services and Business, or GISB Holdings. They included a boy who was seen being caned and another child who was seen being stepped on in online videos, he said.

That brought the number of children under age 18 who have been rescued to 572 since the case against GISB erupted earlier this month, he said,

Police also arrested 156 more suspects for investigation, he said.

Police say some children are believed to have been sodomized and taught to sexually abuse each other, denied medical treatment and burned with hot metal spoons as punishment. Medical screening so far has determined that at least 13 teens were sodomized and 172 children suffered long-term physical and emotional injuries.