Britney Spears has added 50 dates to her Las Vegas residency with new shows including performances on New Year's Eve (31Dec14) and Valentine's Day (14Feb15).

Spears ends her first run of Piece Of Me shows at the Planet Hollywood Hotel & Casino resort on Saturday (17May14), but she'll be back onstage in August (14).

The new dates begin on 15 August (14) and run through until 28 February (15).

Announcing the news on on Monday (12May14), Britney wrote, "Love performing for y'all at @phvegas! So much fun every night. Hope I see your faces at the next round of shows!!"