07/30/2007 at 07:00 AM EDT
A flu-ridden Christina Aguilera
has canceled two concerts in Australia as her world tour nears its end.
Doctors have confirmed that the singer is suffering from a viral upper respiratory tract infection, a high fever and abnormal coughing. She has been ordered to bed rest, forcing her to cancel her Melbourne shows on both Saturday and Monday night.
Aguilera, 26, sent a personal apology to her fans through a spokesman at The Frontier Touring Company:
"Unfortunately, I have fallen ill with a bad flu virus. This is one of the best cities in the world to perform in and I am truly disappointed that I won't be able to share my show with you all. Thank you for all of the continued love and support and I hope to perform for you all again next time."
Several people on Aguilera's tour have come down with bad colds and the flu as Christina's Back To Basics tour wraps up.
"Christina is a real trouper," said promoter Michael Gudinski in a statment. "She is a talented artist who puts her all into her concerts and she is devastated that she can't perform her remaining concerts in Melbourne."
"They have prescribed complete bed rest for the next few days," Gudinski's statement added.
According to the singer's official Web site
, Aguilera has two more tour dates next week in Auckland, New Zealand, where the tour will wrap up.