By Steve Olafson
OKLAHOMA CITY (Reuters) - Football fans at Oklahoma State University, where several people were injured in a post-game celebration, said on Sunday that an announcement to stay off the field was met with laughter from spectators cheering the victory over the rival University of Oklahoma.
Thousands of people surged onto the field, with several seconds left in the game on Saturday night in Stillwater, Oklahoma, tearing down goal posts and singing the school song.
Oklahoma State went into the game ranked third nationally, and the win gave it an outside chance of a berth in the college football's Bowl Championship Series.
Several fans were injured, and one person remained hospitalized on Sunday, OSU spokesman Gary Shutt said.
Eight people were treated at Stillwater Medical Center for injuries ranging from fractured ankles to strained backs, hospital spokeswoman Shyla Eggers said.
Three people were treated at the stadium, Shutt said.
OSU President Burns Hargis said on Sunday the university's policy barring unauthorized people from the field was clear.
"We regret those injuries to a few fans on the field," Hargis said in a statement.
The university announced its policy over a stadium public address system near the end of the game, which Oklahoma State won 44-10 to capture the Big 12 championship, a first for the university.
"Everyone just kind of laughed," said Hodges, 29, a high school basketball coach and OSU fan from Oklahoma City. "Everyone knew what was going to happen."
"It was just very, very chaotic," he said.
The on-field celebration was not unexpected.
"I heard people talking about it the day before. There was all kinds of chatter about it, if they won," said Eggers, the Stillwater hospital spokeswoman, who is an OSU graduate.
Oklahoma State has not beaten Oklahoma in nine years and is typically is overshadowed by Oklahoma's football powerhouse.
The annual game between the rivals is so intense it is known simply as "Bedlam" in newspaper headlines, television reports and everyday conversation in Oklahoma.
(Editing by Corrie MacLaggan and Ellen Wulfhorst)