AMES, Iowa — A student is seriously injured after a rowdy crowd overturned cars and toppled light poles near the Iowa State University campus during an annual celebration designed to showcase the educational establishment, its students and alumni, authorities said today.

Ames Police Cmdr. Geoff Huff said the crowd that massed late Tuesday in the Campustown area of Ames pelted officers with rocks and beer cans. Huff wrote on the police department’s Facebook page that the crowd overturned at least two cars and knocked down two light poles. One of the falling poles apparently struck one reveler, who was taken to a hospital.

The crowd dispersed early today, police said. It was not clear what caused the Veishea celebration to get out of control. Veishea, which dates back decades, was marred by violence in 2004, resulting in dozens of arrests and tens of thousands of dollars in damage. The university canceled the celebration the following year. Other years have had riots, too: 1988 and 1992.

The university’s president, Steven Leath, lamented the students’ behavior and said school officials would decide later today whether the week of Veishea celebrations would continue as planned.

In a statement posted early Wednesday on the university’s website, Leath said an Iowa State student had been seriously injured. He did not identify the student or provide details of the injuries. Police said the student was taken to a local medical center then airlifted to a Des Moines hospital.

“We are all distraught and disappointed over the events that have unfolded near campus overnight,” Leath said.

Authorities said they were seeking tips from the public to help identify those responsible for the trouble.

The Register said a moving crowd blocked streets for more than an hour and that police and firefighters had to press through the throng to reach the injured student.

Iowa State University said on its website that the campus in the U.S. Midwest has drawn more than 33,200 students from across the nation and from more than 100 countries, along with more than 6,300 faculty and staff.