Paris Hilton is turning heads in Miami this weekend as she's been hitting the clubs and smooching with on-again, off-again boyfriend Stavros Niarchos – and according to some eyewitnesses, clashing with club goers.

Sources tell PEOPLE Hilton scuffled with club goers two nights in a row – Thursday at SET nightclub in Miami Beach, and again Friday night at Cameo – but no charges were filed with police and Hilton's rep denies Paris fought with anyone. "Paris did not slap anyone in Miami," the rep tells PEOPLE.

Hilton, 26, and Niarchos, 22, who called it quits again last Spring, are in South Beach for the annual Art Basel art festival and for work. Hilton spent her time in Miami promoting her latest perfume fragrance Can Can at Macy's Dadeland mall. Before the nightclub incidents, the two dined together at the Forge.