Tyson Fury has been extremely active on social media this week. Even more so than usual.Ahead of his return to boxing, the 29-year-old has aimed fire at Anthony Joshua - and received one brutal dig back - questioned whether money and fame really makes a man happy, called a Cambridge councillor racist for his comments about travellers, told everyone how much weight he’s lost and revealed today that he’s out shopping with his wife in London.About half-an-hour after the shopping update, however, Fury sent a tweet containing an ‘open letter’ to Wladimir Klitschko.Klitschko has angered Fury, it seems, with comments he made about Joshua earlier this week.It’s no secret that Klitschko and Joshua have huge mutual respect for one another following their epic bout at Wembley in April - and this, it seems, has irritated Fury.Fury, remember, defeated the Ukrainian in his last fight, back in November 2015. And the Manchester-born fighter feels he doesn’t receive the credit he deserves for that victory from Dr. Steelhammer.

Klitschko: Fury defeat couldn't be my final fight

Earlier this week, in an interview with IB Times, Klitschko said it would have been “terrible” if his career had ended after that defeat against Fury in Dusseldorf.

"My soul and my heart would not be in peace,” he said.

Klitschko: I want Joshua to continue winning

On Joshua, Klitschko added: "I wish for him to win in any other fight that comes up because the more he wins, the more I shine. Because if I lose, I am going to lose to the best man, I just want to be proud of that. He is carrying the flag accordingly."

Klitschko: Joshua is the world's best heavyweight

No doubt these comments have contributed towards Fury taking the time to write up an open letter - although you suspect it was what Klitschko called Joshua which really irked him.

Per BoxingNews24, Klitschko said Joshua is "hands down the world’s best heavyweight."

Fury reacts badly on Twitter

Fury was always bound to react badly - and he hasn't disappointed.

You can read his ‘open letter’ to Klitschko in full here…

Ouch.

Boxing fans react

Here’s how boxing fans have reacted…