Queens of the Stone Age, who were in the midst of a European mini-tour, have canceled their remaining dates and returned to the U.S. after frontman Josh Homme developed a "serious lung infection."

According to the band's official website, doctors in Amsterdam initially diagnosed Homme's illness as the flu, but he later began coughing up blood.

"We've toured with everything from broken ankles to bruised livers, but simply weren't prepared for this relentless attack of teeming bacteria," the band said in a statement. "Our fans know that we ain't p----s and that this is an obvious downer for everyone involved.

" ... So, for those of you with any unused tickets, hold on to them. We'll be back as soon as possible to make up these shows, and when we do, we'll have something special for all of you with an un-ripped ticket. We ain't in the habit of canceling, and we don't forget."

The band is scheduled to launch a North American tour March 15 in Austin, TX; those dates are currently expected to go on as scheduled.