GIRLS ALOUD singer SARAH HARDING has hurt her back and thrown the group's upcoming tour in turmoil, NOTW reports.

Sarah, who recently moved to a new pad in north London, was lifting a heavy box when she pulled a muscle and collapsed in agony. She was rushed to the doctors who have demanded she rest for a MONTH.

Rehearsals for the Tangled Up tour end soon, before the show kicks off next month.

"Sarah is so stressed and in complete agony. She keeps breaking down and crying. Their show is the biggest yet but Sarah is unable to rehearse.

"They may have to change all the routines to accommodate her injury. It's all up in the air."