London, June 19 : Britney Spears made an embarrassing on-stage gaffe by once again forgetting which city she was performing in.

The 27-year-old singer stunned fans in Manchester by announcing: "What''s up, London?"

The singer was appearing at the city''s MEN arena, her only British date outside the capital on her current Circus tour, reports the Sun.

However, some concert-goers were left unimpressed by the mix-up.

It's not Britney''s first foray into audience alienation.

At a show in San Jose, California, in April she asked: "What''s up Sacramento?" (ANI)