August 18 [7:55 EDT] -- Jon Bon Jovi has cancelled or postponed most of the shows on his recently announced concert tour.

The singer was planning a short solo jaunt next month with his back-up band playing select major centers across the country but late Thursday, tickets already on sale and pending on-sale dates were suspended in almost all markets. Mercury Records confirmed the suspentions but did not give a reason for the action. A spokesperson says a press release should be issued later today.

Bon Jovi is certainly healthy. The rocker was in London, England this past weekend performing at the Songs & Visions concert at Wembley Stadium celebrating 40 years of rock along side Rod Stewart, kd lang, Toni Braxton and others. He ably belted out versions of "Heartbreak Hotel" and "Like A Rolling Stone.