British singer Dev Hynes has accused heavy-handed Lollapalooza bouncers of assaulting him and his girlfriend after his Friday (01Aug14) set at the Chicago, Illinois festival.

The Blood Orange star claims he was "jumped by three security guards" after his band's late afternoon performance, insisting, "Everyone saw it."

In a series of tweets on Friday evening, Hynes wrote, "Samantha (Urbani) and I just got assaulted by the security. We are about to press charges... They grabbed her I asked what they were doing and they grabbed my neck and threw me to the ground, then two others joined in on me."

Urbani joined Hynes onstage during Blood Orange's set and urged the crowd to be aware of police brutality issues.

Controversial Hynes also staged a silent protest, wearing a T-shirt that featured the names of African-American victims of violence Eric Garner, Jordan Davis and Trayvon Martin. Garner's 17 July (14) death at the hands of a New York police officer was officially ruled a homicide hours before his set.

He promoted the T-shirt before the gig by posting a photo of himself wearing it and writing, "Samantha & I made this T-shirt which I'm wearing today. The set is dedicated to these names & more. We remember."