AURORA, Colo. >> Three students were shot today during a fight in the parking lot of a high school in the Denver suburb of Aurora, the police chief said, only days after six teenagers from a nearby campus were shot and injured at a park.

Those injured in the lunch-hour shooting outside Hinkley High School are expected to survive, Chief Vanessa Williams said. There were no immediate arrests, and police were trying to determine if any of the injured were among “multiple shooters” in the parking lot, she said.

Friday’s shooting followed another Monday in which six students from Aurora Central High School were the victims of bullets fired from at least one car driving by. Police were working to determine if the two shootings were related, Wilson said.

Police have not arrested anyone yet in Monday’s shootings. The two schools are 3 miles (4.8 kilometers) apart.

Friday’s gunfire erupted during a fight in the Hinkley High parking lot shortly before 12:30 p.m. A school resource officer fired a shot during the fracas and also applied a tourniquet to one of those wounded, Wilson said. No weapons were immediately recovered, she said.

Two of those shot were taken to a hospital, and the third managed to get to a hospital on their own, police said. Two are students at Hinkley and the third is from APS Avenues School, which serves students grades 7-12, Wilson said.

The victims in Monday’s shooting, boys and girls ranging in age from 14 to 18, were all expected to survive. Wilson said Tuesday that two of them had “significant” injuries and faced long recoveries.

Numerous shell casings fired from different guns were found at the scene of Monday’s shooting, and it is possible some rounds were fired by someone on foot, police said. Police have said they have located one of two cars involved in that shooting.

Wilson said police had ramped up their presence at Aurora schools after Monday’s shooting. She also said that she was going to a community peace march inspired by that shooting when she heard about the gunfire at Hinkley High.

As she did on Monday, Wilson expressed frustration that too many guns are in the hands of too many students, and she pleaded with parents to help a police department under pressure to stem the wave of violence among young people.

“People know what happened here. This cannot continue. These kids have guns and they got them from somewhere,” the chief said. “I need the parents’ help on this.”

Wilson said all Aurora public schools would be closed through the Thanksgiving week holiday.

KCNC-TV obtained cellphone video that the TV station said was taken from a car inside the parking lot as shots were being fired. A youth in the vehicle is heard saying, “Oh, no. No, no, no,” and seen crouching as the shots continue ringing out.

Gov. Jared Polis said he was thinking about the injured people in the hospital — and added that the back-to-back shootings are a message that action is needed to curb violence among young people.

“We as a state have to redouble our efforts on public safety,” said Polis, a Democrat.

Yellow crime tape surrounded the parking lot and anxious parents waited outside the campus to be reunited with their children.

As students were allowed out of the building, television images showed them walking calmly and hugging parents.

“Our community rightly is demanding an end to this violence, and we will stand with them in using every tool we have to prosecute aggressively anyone connected to these attacks on students,” said 18th Judicial District Attorney John Kellner.