A melee erupted at Friendly High School in Prince George’s County on Tuesday morning, and investigators speculated that it might have sprung from the fatal shooting of a student late Saturday, authorities said.

Police charged three people, including two Friendly students, with second-degree assault in Tuesday’s disruption, said Lt. William Alexander, a Prince George’s police spokesman. One student, who is 18, will be charged as an adult, along with a 21-year-old relative of a student who was also involved.

Detectives have not made any arrests in the slaying of 16-year-old Marcus Antonio Jones, who was shot about midnight Saturday as he walked to a car in Fort Washington, Alexander said. Detectives say they think that Jones was leaving a house party — supervised by adults and apparently devoid of drugs or alcohol — when he was killed.

“Reportedly, there were no problems inside the party,” Alexander said. He said detectives were still looking for a motive. They said Tuesday’s fight probably stemmed from “emotions running high” over the killing.

School officials said they dispatched grief counselors to Friendly. Police announced they would hold a community meeting Wednesday at the school.

Officers were sent to the school about 7:20 a.m. on a report of a brawl involving as many as 10 people. When they arrived, Alexander said, school security personnel had largely quelled the fight, but another broke out.

Jones’s slaying was the fourth killing of a student in the Prince George’s school system since August.

Briant Coleman, a county schools spokesman, noted that the slayings had all taken place off school grounds.