Detectives have launched an investigation after three children who attended the same nursery school suffered broken bones, police said today
One of the children, a young boy who attended the Rocking Horse Nursery in Plumtree, Nottinghamshire, suffered a broken leg.
The nursery has since had its operating licence suspended for six weeks by the education watchdog Ofsted.
A spokesman for Nottinghamshire Police said all three children were aged between one and two.
He added: "This matter began in mid-August 2009 after a child who attended the Rocking Horse Nursery in Plumtree was taken to hospital with an unexplained fracture.
"In line with the child protection protocol, that child was referred to the children service's department, who in turn referred the matter to Nottinghamshire Police.
"Subsequent inquiries have so far established that two further children who attended the Rocking Horse Nursery had also suffered unexplained fractures this year, and detectives from Nottinghamshire Police's child abuse investigation unit are working with Ofsted and children's services to establish the cause of these injuries.
"All the children involved are aged between one and two years, and officers have questioned five people in connection with the investigation.
"Two of those were arrested and subsequently released on police bail, while the remaining three were questioned under police caution."
The nursery was closed today to children, although one of its directors, Bryn Orme, was working inside.
Toys and children's play equipment were still laid out in the nursery, which can cater for up to 90 children aged 0-5.
It charges parents between £34 and £36 a day to care for a child and also runs a breakfast club and after-school club.
A notice on the front door of the nursery, which had been issued by Ofsted, said: "The purpose of the suspension is to allow time to investigate our belief that a child may be exposed to a risk of harm and for any necessary steps to be taken to eliminate or reduce the risk of harm.
"We will regularly review the situation and will stop suspension within this period if we believe children are no longer at risk."
A spokeswoman for the nursery said: "The directors have not been informed that there is any evidence to suggest that any alleged injury was sustained while the child was in the care of the nursery.
"The directors and all the staff are co-operating fully with the investigation."
A spokeswoman for Ofsted said they were investigating the complaints.
She said: "We have received reports of a number of injuries to children attending the Rocking Horse Nursery and we are working closely with other agencies to investigate and determine the circumstances."
Residents in nearby Keyworth were today surprised at the news.
One 60-year-old woman who did not want to be named, said: "It's not something you expect from a nursery around here, you expect high standards."
Another 63-year-old woman from the village added: "We heard that a child had broken his leg and that there were a few more (children who had been injured)."