U2 disguised themselves as buskers in New York.

The Irish rockers surprised commuters as they performed a secret acoustic gig at the city's Grand Central Station for Jimmy Fallon's 'Tonight Show', which will air on Friday (08.05.15).

Passers-by took to Twitter posting videos of the 'Beautiful Day' hitmakers playing, as shocked New Yorkers were treated to the impromptu set.

One tweet read: ''@jimmyfallon and @U2 dressed as street musicians at a subway station at 10p on a Monday! #gottaloveNYC (sic).''

While another read: ''#U2 at #GrandCentral via @dreyarchives you know. front row at a secret U2 concert in grand central terminal thanks to Jimmy Fallon! #U2 #Bono #theedge #jimmyfallon #tonightshow #grandcentral #nyc #livemusic (sic).''

The band were set to appear on Jimmy's show last year but were forced to postpone after frontman Bono suffered a nasty cycling accident, which has left him unable to play guitar.

He told the New York Times newspaper: ''It's all numb here, and this is titanium.The shoulder's better, the face is better. But this is the hard bit because I can't play guitar.''

U2 are set to kick off the north American leg of their 'Innocence + Experience' tour later this month.