Four people were killed, and four others wounded in a mass shooting Monday night in Philadelphia in the latest chapter of America's gun violence crisis, news reports said.

Philadelphia police spokesman Miguel Torres confirmed to AFP there were multiple gunshot victims but gave no numbers or details.

The Philadelphia Enquirer, CNN and other news outlets reported that a suspect in the shooting in the eastern city's Kingsessing neighborhood had been detained.

The Enquirer said at least two juveniles were among those shot.

It said police detained a man wearing a bullet-proof vest and recovered a rifle and a handgun and additional magazines of ammunition in an alleyway.

The paper described the crime scene as sprawling, with people shot at different locations.

Over the weekend two people were killed and 28 were wounded in a shooting at a block party in Baltimore.

America has now endured 339 mass shootings so far this year, according to the Gun Violence Archive, which defines these as shootings in which four people are killed or wounded.