New York (CNN) -- A free concert in Manhattan by Canadian rapper Drake and pop trio Hanson was canceled Tuesday evening because of an unruly crowd, police said.
"People were throwing bottles, there was people on roofs throwing chairs. It was chaos," one concertgoer told CNN-affiliate NY1.
One third of Hanson, Zac, talked about the incident on his offical Twitter account: "Had to cancel the free NYC show today because of a crazy audience that was breaking things at the mixing board."
The mayhem erupted before Drake, whose widely anticipated new album hit stores Tuesday, took the stage. "NYPD will not let me go on stage tonight," he tweeted shortly before he was supposed to perform.
A spokeswoman for the NYPD disputed the idea that police called off the concert, telling CNN that the event's promoters made that call.
Paper Magazine, a sponsor of the event along with Ray-Ban, explained via Twitter that "the crowd was much larger than we anticipated."
A promotional poster said organizers were expecting a crowd of 10,000-plus.
Two concertgoers were arrested and some others sustained "minor injuries," the NYPD spokeswoman said.