Britney Spears had a spontaneous moment when she paid a visit to a school in New York to sign autographs – but it turned out to be closed.

John Philip Sousa Junior High School in The Bronx was shut for classes because of the Jewish holiday Rosh Hashanah - so teachers had to round up kids that were willing to cut short their break and head back to school to meet their idol.

The glowing pop star signed autographs, beamed for pictures and joked with the thrilled kids.

"I couldn’t say anything – it’s Britney. I was shell-shocked,” one tells OK! magazine.

Brit - who is currently in New York to promote her new single Womanizer - was dangeroudly swamped by fans whilst on a shopping spree on Tuesday.

See a radiant Britney go back to school below & more pics here