WASHINGTON (AFP) - Proud Boys leader Enrique Tarrio was sentenced to five months in prison Monday (Aug 23) for setting a Black Lives Matter banner on fire in Washington as part of protests backing president Donald Trump.

A key figure in the extreme right movement that played a leading role in the Jan 6 attack on the US Capitol, Tarrio was arrested two days before that event for tearing down the banner from a Black church in Washington on Dec 12 and burning it, according to the Justice Department.

He was charged with destruction of property, due in part to a photograph he posted on social media posing with the banner and a lighter in his hand.

Tarrio was also charged with possessing two high-capacity firearm magazines, which are illegal in Washington.

The 37 year old had organised rallies for Mr Trump and against the Black Lives Matter racial justice protests that had swept the country for much of 2020 following police killings and shootings of African Americans.

Late last year, he actively drummed up support for the Jan 6 uprising, which saw hundreds of Mr Trump supporters, including members of violent right wing militia groups like the Proud Boys, invade the halls of the US legislature to stop its certification of Mr Joe Biden as presidential election winner over Mr Trump.

"We are looked at almost like soldiers of the right wing," said Tarrio in a podcast in the runup to Jan 6. "This stuff is real. We are in a war."

But as he arrived in Washington two days earlier, he was arrested on the charges relating to the Dec 12 event, and was ordered to stay out of the city until his court hearing.

In July he pleaded guilty to the charges in a plea deal.

He was sentenced to 155 days in jail and a US$1,000 (S$1,357) fine, as well as US$347 in restitution to the church.