A child prostitution ring uncovered last month in Winnipeg may be larger and more shocking than police first believed.

More than 30 children were victimized in what police are calling the largest case of child prostitution in Winnipeg's history.

Officers say 20 youths between the ages of 12 and 16 were forced to perform sex acts, while 11 others -- some as young as 18 months -- may have witnessed illegal sex acts take place in a home in the city's west end.

Two women are each facing multiple charges related to child prostitution, living off the avails of prostitution, and crimes relating to the corruption of children.

Some of the children are reportedly related to one of the women.

It's not known how long the alleged bawdy house was in operation, but some neighbours told CTV News they've been suspicious about the happenings inside the house for months.

"I see cars going back and forth down the street, picking up girls and they go to that house," said neighbour Alvaro Faria.

Hardy Groening said he saw children around the house when he would pass by at different times during the day, and noticed they weren't in school.

For some child rights activists, the news, sadly, isn't a surprise. Rosalind Prober, president of Beyond Borders, told CTV News there are likely dozens of similar operations in big cities across Canada.

"This is a crime that's happening because there's a demand for it -- and that's shocking, and it's ugly."

Nor is she surprised that women were arrested in the bust.

"Globally, certainly, women are very heavily involved in the sexual exploitation of children," she told Canada AM. "The exploited become the exploiters. There's no reason to be surprised that women are involved in making money off of children when there is a prevalence of booze and drugs, etc."

There could be more arrests and home closures as Winnipeg police continue to investigate. They are urging anyone who may have any information to contact them.

The province's public safety investigations branch has also closed three other homes as a result of this case.

Patrol Sgt. Kelly Dennison said the people who run these sex houses are usually careful to keep the children behind closed doors and out of the sight of police.

It's "the side of the sex trade that people don't see everyday," said Dennison. "And that's the people involved in the business that are working out of bawdy houses or working indoors."

Police last month revealed that the investigation began in September, when they received information about young women being forced into prostitution in Winnipeg's west end.

With reports from CTV's Jill Macyshon and CTV Winnipeg's Rachel Lagace