Two people were dead, 28 were wounded and a manhunt was underway Sunday in Baltimore after a shooting rampage at a block party, authorities said.

Acting Police Commissioner Richard Worley said a 20-year-old man and an 18-year-old woman were killed and that three survivors were in critical condition. Officers were studying video and interviewing witnesses to try and identify suspects, he said.

Mayor Brandon Scott said “every single city agency” will help the neighborhood in its recovery. He urged anyone with information on the killers to come forward.

“This was reckless, cowardly act that happened here that has permanently altered many lives,” Scott said “I want those responsible to hear me, hear me very clearly − we will not stop until we find you. And we will find you.”

Mayor focuses on illegal guns

This tragedy amplifies the need to focus on the alarming number of illegal guns in the city that “make it into the hands of individuals who should not have them” and continuously carry out violent criminal acts, the mayor said. He called for accountability “at each level of the illegal gun trade” − for those using them, those trafficking them and those who manufacture them “in ways they know will lead to violence,” Scott said.

“This act of violence has shaken our city to the very core,” Scott said. “We are all grappling with the shock, pain, and trauma that accompanies such a heinous act of destruction.’

Gunfire was ‘going on and on’

Lakell Nelson, 54, told the Baltimore Sun that hours before the shooting there had been several false alarms of people mistaking the sounds of fireworks for gunfire at the block party. However, when she was leaving, the actual shooting began and “the shots were just going on and on and on.”

Two young women approached her saying they’d been shot.

“I kinda didn’t believe them at first because they were walking up the street. I said, ‘Show me,’ and the girl was like, ‘I was shot in my butt,’” she said. “When she turned around, I saw the hole through her shorts.”

Nelson said she told the women to get in the car and she sped through red lights to the nearest hospital.

Baltimore already suing a gun maker

Brady, the nation’s old gun violence prevention organization, and the city of Baltimore are suing manufacturer Polymer80, the largest “ghost guns” manufacturer, accusing the company of fueling the city’s gun violence. Ghost guns are untraceable firearms that can be bought online and assembled at home. Maryland banned the sale of ghost guns last year. Baltimore police did not reveal the type of firearms used in Sunday’s shooting.

Brady president Kris Brown released a statement warning that July 4th weekend often brings a peak in U.S. gun violence.

“This Independence Day, multiple families will be in mourning because of a uniquely American crisis,” Brown said. “America is the land of the free and the home of the brave, but we will never truly be free until we are free from the daily threat of gun violence. We are reaching a fevered pitch in America where the people’s demand for common-sense gun laws can no longer go unheard by those in power.”

What happened in the Baltimore shooting?

The shooting took place just after 12:30 a.m. in the Brooklyn Homes neighborhood of South Baltimore, Worley said. A woman was declared dead at the scene, and nine victims were transported by ambulance, he said. Twenty victims transported themselves into area hospitals with injuries from the shooting, Worley said.

Scott urged residents to help with the investigation and to assist families of the victims, treating them “how you would want people to treat it if you were mourning, if this was your neighborhood.”

And he had a warning for those behind the carnage.

“I want those who are responsible to hear me, and hear me very clearly,” Scott said. “We will not stop until we find you, and we will find you. Until then, I hope that every single breath you take, that you think about the lives that you took, think about the lives that you impacted here tonight.”

Mass killing database:Revealing trends, details and anguish of every US event since 2006

How many mass shootings have there been this year?

There have been 337 mass shootings in the U.S. so far this year, according to the Gun Violence Archive. And more that 21,000 people have died, reports the archive, which tracks mass shootings.

The archive defines a mass shooting as one in which four or more people are injured or killed, not including the shooters.