At least two people were killed and another 28 injured in a mass shooting in Baltimore in the U.S. state of Maryland, local police said on Sunday morning. 

Police received multiple calls about a shooting just after 12:30 a.m. Sunday (04:30 GMT) in the city's Brooklyn neighborhood, Acting Police Commissioner Rich Worley said during a press conference.

Among the wounded, three are in critical condition.

Worley said authorities were working to identify a suspect and determine a motive for the shooting.

According to Fox News, 20 to 30 shots were fired as people gathered for an event called "Brooklyn Day."