Five senior police officers in India's Noida district of Delhi have been suspended, accused of ignoring local people's fears over missing children.
Local people complained that their concerns were not taken seriously
The skulls of 17 people, most of them children, along with human remains have been discovered near a house in Noida.
A local businessman and his domestic servant have been charged with multiple rapes, murders and kidnappings.
On Sunday, angry local residents forced their way into the house, hurling bricks and vandalising the building.
The police chief of Uttar Pradesh, Bua Singh, said a high-level probe had been ordered into the case.
"There is no denying that this was a case of gross laxity, negligence and failure on the part of some policemen," Mr Singh said.
"They did not pay attention to repeated reports of missing children from the area. Those found guilty will be severely punished."
Furious relatives gathered outside the property, where diggers have uncovered human skeletons in the back garden and plastic bags containing body parts in the front drain.
Human remains were dumped in plastic bags in the drains
Police used batons to control the crowd who turned violent, throwing bricks at the property's windows.
Some managed to force their way into the house.
"My three-and-a-half-year-old son Harsh never returned after he went to play near a wedding hall two months ago," 25-year-old labourer Poonam told Reuters news agency.
"Today, when I went inside the house, I found his clothes."
Lured with sweets
A total of 17 skulls have been discovered. Many of the victims are believed to have been sexually assaulted before being killed.
Police said they began digging around the house on Friday after a domestic servant who worked there admitted that he had raped and killed several children.
The children were reported to have been lured to the house with promises of sweets while the women were offered jobs.
Neighbours are reported to have contacted the police after smelling a foul stench coming from the drain outside the house.
The search for more remains continues. Local people say that almost 40 children have disappeared during recent months.