Barcelona have sacked Sergi Guardiola over a string of abusive tweets, just a few hours after the midfielder signed a contract with the Spanish giants' B team.

The Catalan club confirmed on their official website on Monday that the 24-year-old had put pen to paper on a deal, but shortly afterwards, it was announced that Guardiola's contract had been terminated.

The decision was made after fans informed the club that the midfielder had made offensive claims about Barca on social media in 2013.

A statement from the reigning La Liga champions read: "FC Barcelona has decided to terminate the contract signed with Sergi Guardiola after finding that he had published offensive tweets about the club and Catalonia."

The player himself later told Onda Cero that he did not write the messages and that he was unaware that the tweets existed.

"I apologise to Barca and to Catalonia," said Guardiola. "It is a misunderstanding. I didn't write [the tweets], it was in 2013 and I didn't even know they existed. It was put on my profile, but it wasn't me. I ask for forgiveness a thousand times - I have learnt a difficult lesson."

Barcelona's first team will return to league action on Wednesday following a winter break when they take on Real Betis at Camp Nou.