Lester Chambers, a key member of soul-rock group The Chambers Brothers, was attacked on stage in Hayward, California on Saturday night after apparently dedicating a song to Trayvon Martin.

The 73-year-old Chambers was performing at the Hayward Russell City Blues Festival when a woman, identified by police as 43-year-old Dinalynn Andrews Potter, jumped on stage and knocked the singer down, eyewitnesses say.

The incident was announced by Chambers' son, Dylan, who posted on Facebook that the singer had been assaulted after dedicating Curtis Mayfield and The Impressions' "People Get Ready" to Trayvon Martin. Chambers' wife, Lola, told the Mercury News that her husband had just commented that if Mayfield were alive, he'd change the lyrics from "there's a train a common" to "there's a change a comin'".

"She must have been an acrobat," Lola Chambers said. "She did it in one leap. He didn't see her coming."

According to family friend Kurt Kangas, Andrews Potter apparently yelled "it's all your fault" while rushing the stage.

A Florida jury on Saturday acquitted neighborhood watch volunteer George Zimmerman in the shooting death of 17-year-old Martin. The verdict elicited strong reactions from musicians and members of the entertainment industry.

Police say Andrews Potter was subdued on stage and arrested on suspicion of battery. She was cited and released, but Chambers' family is pushing authorities to file hate crime charges.

Chambers was taken to a hospital and released. A photo posted by Dylan Chambers shows him with a long bruise along the side of his left rib cage. "A bruised rib muscle and nerve damage and he is sore all over," Dylan wrote.

Chambers is a co-founder of the influential group the Chambers Brothers, which had a No. 11 hit in 1968 with the soul-rock classic "The Time Has Come." He sang lead on many of the band's notable songs, including "I Can't Turn You Loose" and their own version of "People Get Ready."