Avril Lavigne has postponed a series of US tour dates after being diagnosed with acute laryngitis.

Four gigs, in Anaheim, Universal City, San Diego and Phoenix were postponed, with four further dates put off for the future.

A message on the Avril Lavigne website explains that the gigs are postponed, although ticket refunds are available to fans. No details of rescheduled tour dates have been released.

In a statement on the website Lavigne said: "My sincerest apologies to all of my fans. My intention was to complete the rest of the tour but tonight at sound check in Anaheim I realised this wasn't possible. Even though I have been resting my voice for days, when I tried to sing nothing came out."

The affected Avril Lavigne tour dates are:

Santa Barbara Bowl (May 6)
San Jose Pavilion (7)
Spokane Arena (9)
Everett Comcast Arena (10)