Bono is “deeply saddened” over the violence in St. Louis, Missouri that forced his band U2 to cancel their Saturday night (16Sep17) concert.

Marchers took to the streets on Friday (15Sep17) to protest the murder acquittal of Jason Stockley, a white St. Louis police officer who shot and killed African-American citizen Anthony Lamar Smith in 2011.

The gathering was initially peaceful, but by the end of the night the demonstration had grown brutal, with nine officers reported injured and 32 arrests taking place.

The incident became so violent, St. Louis law enforcement authorities could no longer police the U2 concert thanks to the number of officers on patrol in the city, prompting the rockers to cancel their concert out of safety concerns.

Bono took to the band’s Instagram account on Saturday to address the cancellation, revealing he is disturbed by the racial violence erupting in the U.S. of late.

“Deeply saddened at what has happened in St. Louis and having to cancel our show tonight….I found myself reading Dr. King’s speech from the National Cathedral and asking myself is this 1968 or 2017?,” he questioned before sharing the following quote by late American civil rights activist Dr. Martin Luther King Jr.: “Human progress never rolls in on the wheels of inevitability….we are coming to ask America to be true to the huge promissory note that it signed years ago. And we are coming to engage in dramatic nonviolent action, to call attention to the gulf between promise and fulfillment; to make the invisible visible.”

U2 isn’t the only act cancelling performances in St. Louis due to the violence – British singer Ed Sheeran has also followed suit by axeing his Sunday (17Sep17) show at the Scottrade Center.

Stockley’s controversial acquittal takes place two years after white police officer Darren Wilson was not indicted for fatally shooting African-American teen Michael Brown in nearby Ferguson, Missouri, sparking similar protests.