The police in San Bernardino, California, say a shooting at an apartment complex Sunday injured eight people, with two of those people in "critical" condition.

The shooting took place in a complex the police said had "a lot of gang activity", but it's too early to tell whether the incident was gang-related.

The police have not recovered any weapons or identified any suspects in connection to the shooting.

The police in San Bernardino, California, say a shooting at an apartment complex Sunday night left eight people injured, with two in critical condition.

"We got a call about 10:45 p.m. for shots fired," Capt. Richard Lawhead of the San Bernardino Police Department said.

A police officer speaking with reporters said no deaths were confirmed. A video posted to the YouTube channel News Now Yucaipa showed what appeared to be an SUV with bullet holes near the scene on Lynwood Drive.

The police previously reported that children had been injured in the shooting, but an officer on the YouTube video said all victims had been adults.

Lawhead went on to say "handguns and rifles" had been used in an exchange of gunfire between two parties. "We do have a lot of gang activity in this area," he said in the video.

"My brother-in-law could hear bullets flying past our house, he was outside at the time of the shooting," Alysa Marie, a local resident told CNN. "About five minutes later the helicopter was circling around our street (Lynwood Drive), talking on the loud speaker saying to put down the weapons, for the people who were on the ground to get up and get to safety and to let the law enforcement do their job."

The police have not recovered any weapons from the incident and reported an uncooperative crowd when officers first responded to the scene. Lawhead said that as of early Monday detectives had not identified any suspects or a motive in the shooting.

"I can tell you multiple shots were fired, I don't want to guess how many," Lawhead said. "We do have some people that have been transported to the station for investigative purposes so we hope that they will yield information for us."

The shooting happened on a hot holiday weekend in the city, which is located about 60 miles east of Los Angeles.

People were gathered outside playing games in a common area of an apartment complex of about 100 units, the police said. Units from multiple agencies had responded.

"Most of the witnesses are being uncooperative, so we're not really sure what happened prior to the shooting," San Bernardino police spokeswoman Sadie Albers said.

The victims include seven adults and a 17-year-old boy. Albers said those critically injured were the 17-year-old and one adult. The six other victims didn't have life-threatening injuries and are expected to survive.

The shooting took place a week after a gunman shot 11 people, two fatally, at a video game tournament in Jacksonville, Florida on August 26.

In December 2015, a couple in San Bernardino opened fire on a nonprofit's office, leaving 14 dead in what the police called an act of terrorism.

Reuters and the Associated Press contributed reporting.