According to news just breaking, police in the United States have issued an appeal following the disappearance of singer Sinead O'Connor.

TMZ are reporting that the Nothing Compares 2U singer was last seen cycling through an area known as Wilmette – a suburb of Chicago – but has has not been seen since yesterday.

It has been established that the Irish star was wearing a black parka, black leather pants and a sweatshirt with "Ireland" on the back, and is understood to have been cycling a motorised Raleigh bicycle with a pink basket.

Fearing for Sinead's safety, officials in Chicago have issued an alert to the press and public, and classified the mum-of- four as 'missing suicidal'.

"The Wilmette Police is seeking to check the well-being of Sinead O'Connor," read the statement from the Wilmette Police Department. "O'Connor reportedly left the Wilmette area for a bicycle ride yesterday at 6:00 a.m. and has not returned. A caller has expressed concern for her well-being and no other information is available at this time."

We're hoping Sinead will be found safe and well.