SULPHUR, Okla. -- The FBI is investigating a threat posing a "grave danger" to an employee at the Oklahoma School for the Deaf in Sulphur.

In a statement issued late Thursday afternoon, the school said the threats demanded that the employee in question be fired within 48 hours.

School is not in session at OSD, but enrollment -- which had been scheduled for Saturday -- is now postponed until further notice.

School officials said the threats appear to be linked to a family member of the OSD employee who "made negative social media statement about a transgender student" attending Achille Public Schools, about 60 miles south of Sulphur.

"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," the school said in a statement. "OSD is fully committed to providing a safe and effective educational program and environment for all the students in their care."

The school also canceled a planned Thursday evening scrimmage against Sasakwa.