Just as The Weeknd was closing his Coachella set on Friday (Apr. 20), his longtime collaborator Belly was reportedly assaulted by the festival’s security staff.

A video obtained by TMZ shows several security guards pummeling Belly, who co-wrote The Weeknd’s hit “The Hills.” They surround him and punch him several times in the clip, but the reason behind the attack is unknown.

Witnesses say that Belly, who also performed at the festival, and a group of people were walking from the sound booth to the VIP section near the stage before the incident took place.

https://www.youtube.com/watch?v=AnfAj9\\_nW4I

The rapper took to Twitter after the incident. “20 of you pussies couldn’t take me off my feet,” he wrote, adding, “no negative bullshit can steal my joy.. I performed the best show of my life, on 4/20 at Coachella!! I really came from nothing, and I’m still here.. it’s gotta mean something.”

The Weeknd and Belly are frequent collaborators. In 2015, they joined forces on “Might Not” off Belly’s mixtape Up for Days. Belly also co-wrote a series of songs for The Weeknd, including “Often,” “The Hills,” “As You Are,” and “Six Feet Under.”