LANSING, Mich. (AP) - Michigan put thousands of lower-income children at risk by authorizing sex offenders and other criminals to provide day care over a period of more than two years, according to a state audit released Tuesday.

The Department of Human Services licensed, registered or enrolled about 1,900 "unsuitable" day care providers, including child abusers and 31 people listed on the public sex offender registry, said Auditor General Thomas McTavish.

About 4,600 children were potentially at risk between October 2003 and March 2006, according to the audit. More than 400 unsuitable providers were previous perpetrators of child abuse or neglect, and 28 had committed crimes such as murder and rape.

A vast majority of the providers were relatives of the children or aides caring for them in the children's' own homes, not licensed homes or facilities. The state pays the providers if their lower-income parents are working or going to school.

In response to the audit's findings, the state stopped paying some providers and began running additional criminal background checks on workers in April 2007 after being informed that its primary background check program wasn't flagging all offenders.

The state also expanded a list of crimes for which providers' services can be ended, started doing background checks on other adults in relatives' homes and did pre-enrollment checks on providers.

"Parents should feel reassured that the department has taken steps to do everything we can to ensure that their children are with a provider who has had a background check," said Lisa Brewer Walraven, director of the Human Services Department's Office of Early Education and Care.

Still, agency officials stressed that parents ultimately decide where their children get day care and in some cases know the backgrounds of relatives or others.