YOUNGSTOWN, Ohio - Two men involved in a dispute at a fraternity house party left the house and then returned, firing shots into the crowd early Sunday and killing a Youngstown State University student and injuring 11 other people, a police chief said.

Youngstown police Chief Jimmy Hughes said the house just north of the Ohio campus had been bustling with 50 or more people, some as young as 17. Six of the injured were students, authorities said.

"These guys were in the location for a little while before the shooting occurred," he said. "Something happened that they became unhappy. They had some type of altercation."

Investigators are trying to identify the shooters based on accounts from eyewitnesses, and the people who were shot have told police they had no problems with the suspected shooters, Hughes said.

"These guys were in the location for a little while before the shooting occurred," he said. "Something happened that they became unhappy. They had some type of altercation."

Members of the university-sanctioned Omega Psi Phi fraternity lived at the house, YSU spokesman Ron Cole said.