One person was hospitalized and 10 people were arrested following a shootout Sunday night with police at a house party in South Los Angeles, police said.

The shooting occurred in the area of 99th Street and Hoover Street around 10:35 p.m., according to the Los Angeles Police Department's Southeast Division.

About 30 people were at the party, police said.

"It's really hard to say what was going on at this party and why this suspect decided to fire on our officers," said Sgt. Barry Montgomery.

People who attended the party described it as a memorial for a man killed during the weekend at a pajama party in Carson.

Several people ran from the party as officers arrived and at least one person fired on police, according to the LAPD. Four officers working gang detail responded to the house, and one returned fire on the subject, police said.

The subject was struck by a round in the right shoulder, police said. No officers were hit by gunfire.

About 10 people were arrested.

NBC4's Jonathan Lloyd contributed to this report.