Britney Spears' Chicago-area fans will be a bit bummed out on Friday night.

Spears suffered a knee injury while performing in Moline, Illinois, on Thursday, forcing her to cancel her Friday night (March 19) performance at the Allstate Arena in the Chicago suburb of Rosemont.

The singer injured herself near the end of the show, during a dance routine for one of her new songs, "(I Got That) Boom Boom." The show was a part of Spears' Onyx Hotel Tour, which kicked off on March 2 in support of her latest album, In the Zone (see "Britney Strips, Gyrates, Sweats, Flirts At Tour Kickoff").

A statement from Spears' label, Jive Records, asked fans to hold on to their tickets until further notice. A representative for the Allstate Arena said the venue is negotiating a makeup date for the middle of April.

Four years ago, Spears underwent surgery after twisting her knee during a dance rehearsal (see "Britney Spears Sidelined For A Month Following Knee Injury").

Spears' spokesperson declined to comment on the nature of the injury or on whether more dates might be nixed.