At least 20 people, including a 13-year-old boy, were injured in a gun attack at an all-night arts festival in Trenton, in the US state of New Jersey, BBC reported.

Police say at least two men opened fire at around 03:00 local time (07:00 GMT) as 1,000 people were enjoying the local art, music and food.

One of the suspects, a 33-year-old man, was shot dead and another is in custody, a local prosecutor said.

Four of the injured, including the teenager, are in a critical condition.

Angelo Nicolo was attending the event with his brother. He told US media that they heard loud popping sounds and people started running down the street.

"I saw two police officers escort a guy that got shot in the leg. They bandaged him up and whisked him away," Mr Nicolo said.