Two people were killed and 28 others wounded in a mass shooting at a block party in the US city of Baltimore, including three who were in critical condition, police say.

According to international media reports, the shooting took place just after 12:30am (04:30 GMT) on Sunday at the party in the Brooklyn Homes area in the southern part of the city, Richard Worley, the Baltimore Police Department’s acting commissioner, told reporters.

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

An 18-year-old woman was found dead at the scene and a 20-year-old man was pronounced dead at a hospital shortly after, police said.

Hundreds of people had gathered in the area for an event called “Brooklyn Day”, a witness told reporters, adding that they had heard 20 to 30 gunshots.

With more firearms than inhabitants, the United States has the highest rate of gun deaths of any developed country – at least 44,357 in 2022, including 24,090 suicides, according to the Gun Violence Archive (GVA).

Sunday’s mass shooting was at least the 337th to occur this year, according to the GVA, which defines a “mass shooting” as a gun-related incident in which four or more people are wounded or killed.