The wave of violence broke out as nearly 20,000 people left Newark's Prudential Center after Saturday's Red Hot Chili Peppers show.
Three teenagers and two adults were targeted, including a 23-year-old Pennsylvania man, who suffered a fractured eye socket.
Newark Police Director Samuel DeMaio tells The Star-Ledger of Newark the suspects appeared to be a band of 10 or 15 "thugs." No arrests have been made.
The attacks came less than a month after the city reduced the number of officers patrolling the arena from 20 to 14. But DeMaio tells the newspaper 23 officers were assigned on Saturday.
___
Information from: The Star-Ledger, http://www.nj.com/starledger