Florence Welch has pulled out of two European festivals after being warned she could permanently damage her voice if she performs.

The lead singer of Florence + The Machine said she had suffered a “vocal injury” and was told she could not sing for a week.

The Grammy-nominated band was due to play at the Benicassim festival in Spain and at the Optimus Alive! festival in Portugal this week.

Apologising to fans for the cancellation of the shows, the redheaded frontwoman explained what had happened on her Twitter account.

"Yes it's true … it finally happened, I've lost my voice," she tweeted. "I've sustained a vocal injury and been told i cannot sing for a week … seriously I felt something snap, it was very frightening."

Welch added: "Unfortunately this means I will not be able to perform at Benicassim and Optimus Alive festival this weekend.

"I'm so sorry to all the fans, I was desperate to still perform, but was told without question not to, so as not to do permanent damage."

Welch, 25, is not the first chart star to suffer a voice injury. Last year Adele was forced to pull out of a number of shows before undergoing surgery for a vocal cord haemorrhage, while John Mayer cancelled tour dates earlier this year due to vocal problems.

Florence + The Machine are in the middle of their summer festival tour, which kicked off in April with the Coachella Valley Music and Arts festival in California. They are due to perform at a number of festivals in the US and Britain during September.

The band are set to top the singles chart with Spectrum (Call My Name) on Sunday according to midweek figures from the Official Charts Company.