Liverpool have apologised "unreservedly" and begun an investigation after their Twitter account appeared to mock the Munich air disaster.

The club's account, @LFC, asked supporters for three songs to be played over the public address system at Anfield before Sunday's Premier League meeting with Manchester United.

A Twitter user responded with three tunes that have been adapted by some Liverpool supporters to make fun of the 1958 tragedy, in which 23 people died, including eight United players.

The user suggested 'Come Fly With Me' by Frank Sinatra, 'Always Look On The Bright Side Of Life' by Monty Python comedian Eric Idle and 'I Like To Move It', a 1994 dance track by Reel 2 Real.

Some fans have changed Idle's song to "Always look on the runway for ice", while the Reel 2 Real track has been altered to "I like to Munich, Munich".

The Liverpool account responded to the suggestion by tweeting: "Have you been sneaking a look at the dressing room iPod?" A deluge of complaints followed, and the tweet was deleted around two hours later.

In a statement, Liverpool said: "Liverpool Football Club responded quickly to correct the error of judgement that was made last night on its official Twitter account in responding to a distasteful and inappropriate tweet. The club took decisive action and the comment was deleted swiftly.

"We apologise, unreservedly, for any offence that was caused by this mistake."

A Manchester United spokesman said: "We welcome the apology."