The letter "Z" has become a staunchly pro-war symbol of Russia's invasion of Ukraine, sported by politicians, athletes and others.

BBC Russian reports that anti-war rock band DDT were set to perform at an auditorium in the central city of Tyumen, only to find "a huge letter Z" had been drawn inside the hall.

The group's lead singer Yuri Shevchuk - who has spoken out against the war and Vladimir Putin several times - told a local journalist the group had refused to play at the site.

He added that DDT had picked another site, without the letter Z, but had not been allowed to perform there either.