An 'active shooter' tweet from a University of Oklahoma campus safety account Friday night prompted a huge response from law enforcement and first responders near the North Oval on campus.

As of 10:35 p.m., officers told News 9 that campus was 'safe.'

OUPD Chief Nate Tarver said a shots-fired call was made at 9:24 p.m. Tarver said the initial call indicated shots were fired in the Bizzell Memorial Library. He added that the call was made to both OU and Norman Police, and that the Oklahoma Highway Patrol, Cleveland County Sheriff's Office, and Moore Police responded. Hundreds of law enforcement personnel responded to campus.

Here's the alert that was sent Friday night:

A spokesperson for Oklahoma Gov. Kevin Stitt said, "We take these things seriously and are proud of Commissioner Tipton, OHP and all involved law enforcement’s immediate response and investigation on the scene."

The governor's office also said that local, state, and federal law enforcement are working to identify the cell phones used to call the active shooter threat in.

This is a developing story. Refresh this page for updates.