Updated June 5, 2022 at 8:17 PM ET

A string of shootings left at least 15 people dead and more than 60 others wounded in eight states this weekend, a spasm of gun violence that came as the nation continues mourning the lives lost in mass shootings last month in Buffalo, N.Y., and Uvalde, Texas.

In Pennsylvania, police say multiple shooters fired into a crowd late Saturday night on South Street, a famous Philadelphia drag known for its nightlife, character and vibrancy. Authorities said three people were killed by the gunfire, and at least 11 others were wounded. Police said multiple handguns were recovered at the scene, but no arrests have been made.

"Once again, we see lives lost and people injured in yet another horrendous, brazen and despicable act of gun violence," Philadelphia Mayor Jim Kenney said in a statement on Sunday.

Gunfire in Chattanooga leads to three dead

In Chattanooga, Tenn., police responded early Sunday to a shooting near a nightclub. Three people were killed and 14 others were injured, according to police chief Celeste Murphy.

Two people died from gunshot wounds, while a third person died of injuries after being hit by a vehicle, Murphy said. The police chief said multiple people are thought to have opened fire, but no arrests had been made as of Sunday afternoon. Last week, six people were wounded in a gunfire exchange in downtown Chattanooga.

Bullets tore apart a graduation party in South Carolina

Meanwhile, in South Carolina, at least eight people were shot at a graduation party in what authorities in Clarendon County described as a suspected drive-by shooting. A 32-year-old woman was killed, while seven others were wounded. Six of the seven injured were age 17 or younger, authorities said.

Police say the incident may have been gang-related.

"This was a school graduation party and you've got all these innocent children that were there that were hit by gunfire," Sheriff Tim Baxley said.

Multiple weekend shootings rattle Arizona

A 14-year-old girl was killed and eight others were injured during a shooting early Saturday at a Phoenix strip mall, The Associated Press reported.

Nine people were hospitalized, including the 14 year-old girl, who later died. Two women were transported with life-threatening injuries.

"Seems we can't go a day without another mass shooting," Phoenix Mayor Kate Gallego tweeted Saturday. "This time, it's Phoenix, at 10th Ave & Hatcher. Time has run out. Change must happen now."

The next day, a shooting outside a bar in Mesa, Ariz. early Sunday morning left two people dead and two others injured, according to the AP.

156 days, at least 240 mass shootings

Mass shootings also happened in Texas, Georgia, New York and Michigan over the weekend, according to the Gun Violence Archive, a group that tracks mass shootings.

Some 156 days into 2022, the country has now seen at least 246 mass shootings, according to the group's tally. That puts the U.S. on track for one of the deadliest years on record since the archive began tracking gun deaths. The site defines a mass shooting as any incident in which four or more people are killed or injured by a gun.

Since May 14, when a racist attack at a Buffalo, N.Y., supermarket took the lives of 10 people, there have been at least four dozen mass shootings in the U.S., according to data from the group. That includes the attack on Robb Elementary School in Uvalde, Texas that left 19 students and two teachers dead.

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