Activist artists in the Czech Republic have hoisted a giant pair of red underpants up the flagpole of Prague Castle, in a protest against the country's President, Milos Zeman.

As reported by the Prague Post, the group of three men from the Ztohoven art collective climbed onto the roof of the President's office in Prague Castle, under the guise of chimney sweeps.

Once on the roof, they lowered the Presidential flag and replaced it with the giant pair of pants.

On their website, Ztohoven released a statement, saying: "Today we hung a banner over the castle for a man who is not ashamed of anything."

The statement also included a short poem that criticised President Zeman for his close ties to China and Russia.

The pants were quickly removed by security after the stunt, and the three men were arrested.