At least 13 people were hurt in a mass shooting during a party at a campground in Oklahoma on Sunday night, authorities said.

The shooting took place at Spring Creek Park on Arcadia Lake about 15 miles north-east of downtown Oklahoma City, when gunfire erupted during a gathering of young people at about 9pm.

Edmond police department spokesperson Emily Ward said in a media briefing late Sunday that no arrests had been made. Local CBS affiliate 9News reported that the site of the shooting, in a heavily wooded area, had slowed the search for evidence and a possible suspect.

“This is obviously a very terrifying situation and we understand the concern from the public and those involved and we are working extremely hard to find the suspects,” Ward said.

“We’re kind of all over the metro speaking with victims and witnesses.”

According to the Gun Violence Archive, the case in Edmond was the 131st mass shooting in the US so far this year. The group considers a mass shooting to be any incident in which at least four victims are injured or killed, not including the shooter.

Consistently high rates of mass shootings in the US have prompted pleas from some quarters for more substantial gun control. But Congress has not heeded those calls over the years.

Ten of the victims from Sunday’s violence were taken to hospital by ambulance, and several others were able to drive themselves, Ward said. She said those hurt were in “various conditions”.

A witness who identified himself as Armani Kessee told KWTV News in a video posted to Instagram that he and a friend had helped a female victim who was shot.

“She said she had got hit with a stray bullet,” he said. “It’s very sad to see someone that you know, that you love … it’s a very hard thing.”

Health officials said 10 people were at Integris Health Baptist medical center in Oklahoma City, and three were at Integris Health Edmond hospital as of Monday morning.

The Associated Press reported that a flyer on social media had promoted an event called Sunday Funday that was scheduled to take place at Spring Creek Park on Sunday evening. Arcadia Lake is an artificial reservoir popular with anglers, boaters and campers.

Edmond is a suburb of Oklahoma City with about 100,000 residents, the AP said. The city was the site of a deadly workplace shooting in August 1986 when postal worker Patrick Sherrill, a former marine, shot 20 coworkers, killing 14 of them, before taking his own life.

The Associated Press contributed to this report