Prince George’s County, Maryland state, Berwyn Heights and Greenbelt police all responded for traffic and crowd control when, shortly before 3 p.m., officers walking in the park heard multiple gunshots through the crowd, authorities said.

Greenbelt Police Chief Richard Bowers said eight to 10 gunshots went off near a pavilion inside the park. Police said the teenagers had been engaged in a water gun fight.

“The students at the park began to flee in mass out of the park onto Hanover Parkway and we believe the suspect was able to escape with the crowd,” Greenbelt police said in a news release.

Bowers said the five victims were all males between 16 to 18 years old. The Prince George’s Fire Department said the victims were taken to hospitals. No arrests had been made as of late Friday afternoon, but Bowers said police are looking for one shooter believed to be the same age as others at the park.

Eleanor Roosevelt High School nearby was placed on lockdown because of the shooting, and afternoon activities were canceled.

“It’s really concerning that you have a group of kids in a park and it turns violent like this for no apparent reason,” Bowers said.

Bowers said police will work through the weekend to investigate, work that will include scrubbing police body-camera video and cellphone videos from people at the park.

“We did not know that [the skip day] was going to occur,” he said. “We do everything we can to monitor that park,” which sits across the street from the police station.

Prince George’s is one of many jurisdictions in the region trying to stem increasing youth violence. More adolescents than adults have been arrested on carjacking charges in the county in the past three years. And last year, 92 juveniles were arrested on suspicion of possessing a gun, according to county police department data.

To address youth violence, school officials have approved metal detectors on campuses and required clear backpacks. Youth in recent years were subject to a countywide juvenile curfew. And the county launched a program where adult volunteers monitor certain streets that students use to get to school to discourage bullying, fighting and other misbehavior.

Though crime overall is down in Prince George’s County compared to the same time last year, as of Thursday, violent crime is up by about 9 percent. Police data shows that assaults investigated by Prince George’s police are up 17 percent, with 511 cases reported this year compared to 436 for the same time last year. As of Thursday, county police have investigated 71 nonfatal shootings in Prince George’s, down from 76 the same time last year.

The shooting in Greenbelt occurred about 2½ hours after three men and a 16-year-old were wounded in a shooting while gathered in a parking lot in the Trinidad neighborhood of Northeast Washington. A D.C. police spokesman said investigators do not believe the shootings in the District and in Maryland are related.

The shooting in D.C. occurred about 12:20 p.m. in the 1200 block of Mount Olivet Road NE when one or more occupants of a four-door sedan shot at people in the parking lot.

Darnell Robinson, an assistant D.C. police chief, told reporters that the sedan never came to a stop as the shots were fired. He said the victims scattered after the shooting. The wounded men were taken to a hospital in ambulances, and the male teenager showed up at a hospital a short time later.

Robinson said police found the vehicle in the District but had not made an arrest as of Friday afternoon. In March, Mount Olivet Road was included in one of the District’s Drug Free Zones, temporary areas allowing police more authority to confront people suspected of illegal drug activity.

D.C. police said they do not know of a motive in Friday’s shooting, which occurred on a street singled out by an advisory neighborhood commissioner as a problem area. The commissioner said in March that people gather along Mount Olivet Road and that sometimes they have firearms.

“That is what we want police to focus on,” the neighborhood commissioner said.

Crime overall in D.C. is down, with violent crime down 22 percent compared to the same time last year, according to police data.

Nicole Asbury contributed to this report.