Chesapeake: A Walmart employee killed six people and wounded several others before fatally shooting himself at a store in Chesapeake, Virginia, authorities said on Wednesday, in the latest episode of gun violence in the United States.

The shooter, who has not been identified, used a pistol in the shooting late Tuesday, wounding at least four people in addition to the fatalities, Chesapeake Police Chief Mark Solesky said at a news conference.

Coming on the heels of the killing of five people at a Colorado Springs LGBTQ nightclub on Saturday, the latest massacre prompted another round of condemnations by public officials and calls by activists for tighter gun control.

US President Joe Biden on Wednesday called the shooting "yet another horrific and senseless act of violence," vowing any federal resources needed to aid in the investigation.

"There are now even more tables across the country that will have empty seats this Thanksgiving," he said in a statement, noting a shooting earlier this month that left three University of Virginia students dead. "We must take greater action."

In addition to seven confirmed dead, including the shooter, four people were being treated at area hospitals, Solesky said.

Employees told media that the shooter was a manager at the cavernous Walmart Supercenter just off Battlefield Boulevard in Chesapeake, a city of about 250,000 people south of Norfolk.

"I looked up and my manager just opened the door and he just opened fire," Briana Tyler said, according to ABC News.

"The Battlefield Walmart just got shot up by one of my managers. He killed a couple of people. By the grace of God I made it out," another employee, Kevin Harper, told CBS.

Tuesday's bloodshed marked the latest spasm of gun violence in the United States, where an average of two mass shootings -- defined as an incident killing or injuring four or more people -- occur every day, according to data from GunViolenceArchive.org.

Virginia Governor Glenn Youngkin, who was already facing stepped-up calls for policies to address gun violence in the wake of the University of Virginia killings, said he had offered local law enforcement assistance in its investigation.

"Heinous acts of violence have no place in our communities," Youngkin wrote on Twitter.

It is not the first mass shooting at a Walmart, which has thousands of stores across the United States.

At a Walmart in El Paso, Texas, in August 2019, 23 people were killed in a mass shooting near the US-Mexico border in an act described as domestic terrorism by law enforcement. It was also the deadliest attack on the Hispanic community in modern times. Patrick Wood Crusius, then 21, from Allen, Texas, was arrested in the shooting and he left behind a manifesto with white nationalist and anti-immigrant themes.

Walmart in a statement on Wednesday said it was "shocked" at the violence at the Chesapeake store and it was working closely with law enforcement.