An emergency tornado warning was in effect early Sunday on the University of Oklahoma's Norman campus, officials said.

The warning was posted at 1:22 a.m. on the school's official X account. The school issued additional warnings at 1:55 a.m and 2:02 a.m.

"Seek shelter NOW inside the building you are in," the first message said. "Move to lowest floor/interior."

This is a developing story. Please check back for updates.