Pop star Pink has scrapped two U.S. shows after a doctor placed her on vocal rest.

The Trouble singer took to Twitter.com on Wednesday (16Oct13) to alert fans to the cancellations of shows in Utah and Colorado.

She wrote, "Not very dramatic - doctor just wants me on complete vocal rest for four days to heal. So I can kick a**."

The two axed shows in Salt Lake City on Thursday night (17Oct13) and Denver on Friday (18Oct13) have been rescheduled for 29 and 30 October.

Pink followed up her first tweet by adding, "Touring would be terribly easy if I lip synced."