Bieber, 19, was performing when a member of the audience threw what is reported to be a water bottle at him. Video of the incident is below.
According to reports, fans waited for more than an hour in hopes that Bieber would come back to the stage and finish his show. He did not return though, and the show ended without notice. Bieber was performing one of his signature encore songs "Boyfriend" when the water bottle was thrown, so he may have just wrapped his concert (almost) as planned.
"We had a good time tonight. brazil goes hard," Bieber later wrote on Twitter. "U all were loud tonight. thanks for the love. it's all love. all the time. Obrigado Brazil! On to the next one."
Watch the video here: