ROCHESTER, N.Y. (AP) — Two women died and five other people were wounded when gunfire erupted Sunday evening at a crowded public park in Rochester, New York.

Hundreds of people were at an all-day gathering in Rochester’s Maplewood Park when the shooting started around 6:20 p.m., authorities said. Investigators were still trying Monday to determine what prompted the violence and who was responsible, but Police Chief David Smith said multiple weapons were fired.

“I looked up and I hear somebody yell. He’s got a gun! Run!” Rochester resident Shelly Strong told reporters near the scene.

Tyasia Manning, 25, a city employee, was killed, police said. A second victim, Phylicia Council, 34, died later.

The five other people hit by bullets suffered graze wounds and other injuries that weren’t life-threatening, authorities said at a news conference Monday.

Before the violence, “people were in a celebratory mood, enjoying the warm weather, having a good time,” Mayor Malik Evans said. He recalled seeing a stroller and people’s shoes at the park in the aftermath.

“Our people, our residents should be able to enjoy the summer in a park. Period. But all too often we have individuals in this community that are unmitigated cowards, that are OK with shooting women. And two of those women lost their life,” the mayor said.

No suspects were in custody, police said.

Videos posted on social media by people at the park showed people running after the gunfire began and then civilians performing CPR on one victim before medics arrived. Dozens of shots can be heard.

Maplewood Park runs along the banks of the Genesee River on a stretch between the city’s center and Lake Ontario.

Police said the gathering there had been advertised with flyers. They did not specify the occasion but said the organizers were not required to obtain a permit from the city in advance.

“There were hundreds of people at this barbecue, and therefore there are hundreds of people who have potential information to help us solve this crime,” Smith said, urging those with video or information to contact police.

It was the second mass shooting at a Rochester park in as many months.

In June, six people were wounded in an overnight shooting at Dr. Martin Luther King Jr. Memorial Park. Smith said at least one person started shooting into a crowd of people during an argument.

In that case, the shooting occurred at an unauthorized gathering when the park was closed.

Capt. Greg Bello said it was unknown Sunday how many people fired guns during the latest shooting. “We are trying to work our way through as many witnesses as we can,” he said.

Rochester is the second largest city in upstate New York, about 65 miles (105 kilometers) east of Buffalo.