SULPHUR, Oklahoma - The Oklahoma School for the Deaf announced Thursday it would be closing down campus while police investigate a threat against the school.

In a press release, the school located in Sulphur, Oklahoma, said it got a threatening phone call at 12:22 p.m. Thursday threatening "grave danger" to anybody associated with a certain school employee unless that person is fired within 48 hours.

While school is not in session, enrollment was scheduled for Saturday. That has been postponed until further notice, officials confirmed.

School officials believe that the threatening phone call is connected with a series of social media posts, phone calls and emails. The communications alleged that a family member of the employee has made negative social media statement about a transgender student attending Achille Independent Schools.

The Oklahoma School for the Deaf and its parent agency Oklahoma Department of Rehabilitation Services do not tolerate discrimination and take appropriate action based on evidence. OSD is fully committed to providing a safe and effective educational program and environment for all the students in their care.