The Heartbeat hitmaker apologised to fans in several posts on on Friday (11Sep15), explaining she is acting on doctor's orders and the axing of her Piece by Piece tour dates were "absolutely necessary".

She writes, "So bummed that I have to cancel some of my tour dates. This kills me, but doctors are saying I need to rest my voice.... I can't wait to get healthy and see y'all back on the road soon. I hate cancelling... and I am truly sorry to my fans that have been excited to see this show. Please know that I never cancel anything unless it's absolutely necessary.

The cancelled shows, in Virginia, Florida, North Carolina and New Jersey, were due to take place between 12 and 20 September (15). All tickets will be refunded.