Pop star Justin Bieber, known more for headline-grabbing scandals than activism, on Friday took an unexpected political turn as he hailed the Black Lives Matter movement.

The 23-year-old, who abruptly cut short a tour in July, took to Instagram to show support for the movement that has arisen in response to police killings of African Americans.

"I am a white Canadian and I will never know what it feels like to be an African American but what I do know is I am willing to stand up and use my voice to shine light on racism," he wrote.

"It's a real thing and it's more prevalent now than I have ever seen in my lifetime," he wrote, adding: "We're all God's children and we are ALL EQUAL."

The former child star has generally steered clear of politics at a time that the US-based entertainment world is overwhelmingly opposed to President Donald Trump's conservative agenda.

A graduate of Catholic schools and a self-described Christian, Bieber in a 2011 interview denounced abortion as murder but he has been careful not to discuss politics since then.

Bieber last month said he needed to work out some "insecurities" as he explained his need for time to himself amid wide speculation as to the reason for his tour cancellation.

Bieber -- who scored a mega-hit earlier this year with a remix of Puerto Rican star Luis Fonsi's "Despacito" -- in July accidentally struck a photographer with a car in his latest off-stage antic.

Source: AFP