RACINE, WIS. -- Two people were shot at a cemetery south of Milwaukee on Thursday, police said.

Racine police described the shooting as a "critical" incident and urged people to stay away. Police said multiple shots were fired in the direction of a funeral service Thursday afternoon.

Sgt. Kristi Wilcox said a juvenile was treated and released and a second person was flown to a hospital in Milwaukee. It was not immediately known if any suspects were in custody.

Racine police said on social media that numerous shots were fired about 2:30 p.m. at Graceland Cemetery in Racine, about 30 miles (48 kilometres) south of Milwaukee. Ascension All Saints Hospital, which is next to the cemetery, said it is treating an undisclosed number of victims from the shooting.

The shooting comes the day after a gunman killed his surgeon and three other people at a Tulsa medical office. It's the latest in a series of mass shootings in United States including the deadly school shooting in Uvalde, Texas, and an attack on a supermarket in Buffalo, New York.

Ascension All Saints Hospital in Racine was on lockdown "out of an abundance of caution" following the shooting, the hospital said in a statement. It later lifted the lockdown.

Racine Mayor Cory Mason released a statement saying the "heinous shooting at a cemetery while a family was already mourning the loss of a loved one is a new low for these perpetrators of violence in our community. The violence has got to stop!"

Mason said he was instructing the police department to actively enforce the city's juvenile curfew ordinance through the weekend, meaning anyone under 18 must be home by 11 p.m.

Area residents said they heard 20 to 30 shots, the Racine Journal Times reported.

Three young men who were playing basketball at Lockwood Park, immediately west of the cemetery, said they heard shots and the fence behind them was repeatedly hit.

Tre Brantley, one of the men, started running to his car the moment he heard shots. He and his brother, Kellyn Foster, both got into their car and ducked down, praying they wouldn't get hurt.

"This has got to stop," Brantley said of the gun violence.

The shooting occurred at the interment for Da'Shontay L. King Sr., who was fatally shot by Racine police May 20, King's sister, Natasha Mullen said.

"We were at the gravesite trying to get prepared to bury him, and bullets started flying everywhere," she told the Milwaukee Journal Sentinel.

A Racine police officer fatally shot King, 37, during a traffic stop about two weeks ago. Police said they were carrying out a search warrant on a vehicle when King, who they said had a handgun, ran from the car. According to police, King ignored commands to drop the weapon and Officer Zachary B. Brenner shot him.

The Department of Justice is investigating the shooting.

Police are asking people to avoid the area in west Racine around the cemetery.

Correction:

This story has been corrected to show that police say King ignored commands to drop the weapon.