NARRAGANSETT — It was a birthday party that turned into a brawl, injuring several people and sending one to the hospital with serious facial injuries, the police say.

Yesterday the police announced the results of their investigation: 11 arrests, including three members of the men’s lacrosse team at the University of Rhode Island and three members of the women’s lacrosse team.

Just who is responsible for the injuries to the man who needed surgery is unclear because people have not cooperated with the investigation, said Detective Lt. William McGovern.

What is clear, McGovern said, is that the April 3 event at a house at 42 Middle Rd., which is rented by women’s lacrosse team members, started as a birthday party.

Someone invited members of the men’s lacrosse team, who were later asked to leave. Most of them did, said McGovern and Thomas R. Dougan, URI’s vice president of student affairs, but one realized he had forgotten a sweatshirt or game jersey and went back to the house with three friends to get it.

“That’s when a confrontation took place in the house,” McGovern said. “It went out into the yard, then it became physical and it ended up in the street.”

Officers responded to 911 calls at about 1:50 a.m. on April 4. They found a young man “in the middle of the road, in a large pool of blood,” McGovern said.

The URI student was taken to South County Hospital and transferred to Rhode Island Hospital, where he had surgery, McGovern said. Injuries to others were less serious, but they included a broken hand, black eyes and lacerations, he said.

Over the past week, the police arrested seven people and charged them with simple assault and disorderly conduct: Sally E. Dowd, 22, of 42 Middle Rd., Narragansett; Frederick Ecke, 22, of 281 Kingstown Rd., Narragansett; Kevin Labove, 22, of 281 Kingstown Rd.; Justin H. Taylor, 22, of 281 Kingstown Rd.; Alexandra Pisciotto, 21, of 42 Middle Rd., Narragansett; Glenn A. Scott, 20, of 147 Sedge Field Rd., North Kingstown; and Gillian B. Spealman, 22, of 10 Rollens Drive D2, South Kingstown.

Four others were arrested and charged with disorderly conduct: Marc A. Acciani, 22, of 281 Kingstown Rd.; Bryan P. Giannecchini, 22, of 3 Hemlock Ave., Narragansett; Gregory J. Miller, 20, of 41 Orton Rd., West Caldwell, N.J.; and Matthew T. Merola, 19, of 520 Eddy Hall, South Kingstown.

Dougan said all 11 are enrolled at URI except Scott, who is a former student. He said the university will be calling students in and will determine what, if any, action should be taken. The action could range from a reprimand to expulsion, he said.

redgar@projo.com