Originally Published: 18 APR 22 12:44 ET

By Elizabeth Wolfe, CNN

(CNN) -- At least 10 mass shootings across the US this weekend left eight people dead and dozens injured, disrupting gatherings including an Easter celebration and a massive house party.

The shootings add to the year's increasing toll of mass shootings in the United States, which stands at 144, according to the Gun Violence Archive. The archive and CNN define a mass shooting as an incident in which four or more people are shot, not including the shooter.

The violent weekend follows a horrifying attack Tuesday on a Brooklyn subway train that left almost 30 people injured, including 10 shot.

Easy access to guns is considered by experts to be a root cause of gun violence, and open-carry states lower the barrier for people to own and carry guns in public. But the spike in violence across America since summer 2020 has been general, across cities and states with lax and strict gun laws, with progressive and conservative prosecutors, and with Republican and Democratic mayors and governors.

From parties to a shopping mall, here's a look at the mass shootings this weekend that spanned eight states.

California

A late-night Friday incident in Stockton left two men dead and two others wounded, according to the Stockton Police Department.

When police arrived around 11:20 p.m. PT, they found four men shot, Stockton police said in an online statement. Two of the men, ages 26 and 27, were pronounced dead, and two other victims were taken to a hospital, police said.

No suspect or motive was immediately identified in the attack, the police statement said.

Florida

Police are investigating a Sunday night shooting that left one man dead and three others injured, said Miami-Dade Police Department Det. Alvaro Zabaleta.

Officers responded to a shooting at a residence in the 5000 block of South River Drive just before 10 p.m. ET, Zabaleta said Monday.

"As the officers arrived, they discovered four people shot," he said. "An adult male was shot, an adult female was grazed and two juveniles were shot in the lower extremities."

Police did not disclose the ages of the people injured.

Investigators are working "to determine who the shooter may have been and if this incident is domestic related," Zabaleta said.

Maryland

In Baltimore, a Saturday evening shooting left one victim dead and three others injured, police said.

When police responded around 5:30 p.m. ET to a report of a shooting in the 5300 block of Maple Avenue, they found two men with gunshot wounds, police said.

Medics pronounced a 29-year-old dead at the scene, while the other man was taken to the hospital with injuries that were not life-threatening.

Investigators later learned two other men at a hospital had been victims in the Maple Avenue shooting, police said.

Nevada

A shooting late Saturday at a house party in North Las Vegas left four people injured, including two minors, CNN affiliate KVVU reported, citing police.

One woman was shot on her lower extremities and was in serious condition, and other victims were in stable condition Sunday afternoon, KVVU reported.

No suspect was in custody by Sunday evening, the station reported.

New York

One person was killed and four others wounded early Saturday morning in downtown Syracuse as gunfire erupted in part of the nightlife district, CNN affiliate WSTM reported.

The shooting happened after a verbal argument, police said, according to WSTM. In addition to the person killed, one victim was taken to the hospital in critical condition, the affiliate reports.

Alexandra Campbell was finishing her shift at a nearby restaurant when the shooting broke out. After hiding behind her workstation, she came out and saw the aftermath, she told WSTM.

"I just see blood everywhere, a lot of blood," Campbell said. "I didn't really know what to do. I was crying."

Oregon

A male was found dead and three boys wounded by gunfire Sunday night in Portland's Centennial Neighborhood, police said in a news release.

Officers responding at 8:43 p.m. PT to the 500 block of Southeast 162nd Avenue found a person dead and three boys shot, one with life-threatening injuries, it said. They were taken to hospitals.

Pennsylvania

Two mass shootings Sunday left two dead and at least 17 injured.

A party at a short-term rental property in Pittsburgh ended abruptly early Sunday when as many as 90 shots were fired inside and outside the house, leaving two 17-year-old boys dead and more than a dozen other people injured, officials said Sunday.

Investigators say as many as 200 people were at the gathering, many of them underage. When the shooting broke out, some escaped by jumping out windows, resulting in injuries including cuts and broken bones, the city said in a news release.

Eight people had nonfatal gunshot wounds, and five others were hurt fleeing, Chief Scott Schubert said.

A massive search effort is underway for what police believe are "multiple shooters," they said.

Later in the day, four men were shot in Philadelphia's Fairhill neighborhood, CNN affiliate KYW reports.

Victims, ranging from 21 to 53, were shot around 6 p.m. ET and are in stable condition, police said, the station reported.

South Carolina

Shootings at an Easter celebration and a shopping mall left at least 23 people injured, including 18 who were shot.

One man has been arrested in connection with a shooting Saturday at the Columbiana Centre mall in Columbia that left at least nine people with gunshot wounds and five others injured, the Columbia Police Department said in a news release.

Around 2 p.m. ET, armed people clashed inside the mall, police said. Investigators believe those involved in the shooting knew each other, Chief William "Skip" Holbrook said Saturday.

A suspect was arrested, police said. The victims' ages range from 15 to 73, police said.

Another shooting Sunday morning in Furman at a lounge hosting an Easter party left at least nine people injured, according to the South Carolina Law Enforcement Division.

Chaos followed the gunfire at Cara's Lounge, witnesses said, and some people jumped into ditches to avoid being hit, CNN affiliate WTOC reported.

"It was scary. We were just trying to get to safety," Jasasi Williams told WTOC. "We didn't know where the shots were coming from. ... Everyone was running and screaming."

Furman is about 50 miles north of Savannah, Georgia.