Justin Bieber has been filmed appearing to punch a man after he reached into the pop star's car in Barcelona.
Video footage showed the 22-year-old singer lash out at the man who tried to touch him through the open window of his moving vehicle.
The video, posted online by celebrity news website TMZ, shows the man then turn to the camera afterwards to reveal he has a bloodied mouth.
Bieber had performed in the Spanish city on Tuesday night as part of the European leg of his Purpose world tour.
Last month the Canadian star stormed off stage during a concert in Manchester after complaining about his "screaming" fans.
After leaving the stage, he returned to continue his performance, saying he was "going to quit talking" for the rest of the night.
During his UK tour in 2013, Bieber burst out of a vehicle and lunged at a photographer in an incident which was also caught on camera.
A representative for Bieber could not be immediately reached.