Some parents who received an anonymous letter alleging sexual abuse at their children’s elementary school say that they want to know who sent the letter and why.

Over 50 parents at Glenwood Elementary School in the Short Hills section of Millburn received the letter, which states that the children might be sexually assaulted by a group of adults at the school. The letter instructs the parents to take their children to a hospital that they could trust that is far away from Short Hills.

The Millburn Police Department and school district have said that the letters are a hoax and that no sexual assault has taken place at the school. But it has still left parents feeling uneasy.

“I read the letter and I was just absolutely shaking,” says parent Missy Rodriguez. “So odd. So abnormal…I was just in absolute shock.

The letter also stated that school district is “treated to keep this secret every day.”

Rodriguez says that she trusts the staff at Glenwood Elementary and believes the letters to be a hoax. But she says that there should be greater communication between the school and parents.

"Even if the abuse isn't true and in my heart of hearts I don't believe it’s true…But someone did take the time to do this and I would like find out what's going on with that,” she says.

The Millburn school superintendent says in a statement, "We have tightened our arrival and dismissal procedures even further to a heightened security level. Our principals and staff have been alerted to be aware of anything out of the ordinary."

The typed letters were all addressed to the husbands of the households. The postmarks were from either St. Paul, Minnesota or Milwaukee, Wisconsin.

News 12 New Jersey has reached out to the Millburn Police Department for more information about the investigation, but has not heard back.