Two people were killed and 28 were wounded in a mass shooting in Baltimore on Sunday morning, including three who are in critical condition, police have said.

Baltimore police department acting commissioner, Richard Worley, confirmed there were a total of 30 victims during a press conference at the scene.

The shooting took place just after 12.30am at a street party in the Brooklyn Homes area of South Baltimore in the 800 block of Gretna Avenue, Worley said.

All of the victims were adults. Nine victims were transported by ambulance and 20 victims walked into area hospitals with injuries from the shooting, Mr Worley said.

“I want those who are responsible to hear me, and hear me very clearly,” mayor Brandon Scott said at the scene.

“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.”

No arrests were made immediately after the shooting.

Mr Scott asked anyone with information to come forward to assist investigators locate the “cowards” who were responsible for the shooting.

“Treat this as if it were your family,” Mr Scott said. “How you would want people to treat it if you were mourning, if this was your neighbourhood, if this was an event in your community that this happened at.

“We want you to treat it that way because that’s how we have to treat each other as Baltimoreans.”