Billie Joe Armstrong, the front man of rock group Green Day, has entered treatment for substance abuse, according to a statement on the band's website.
The announcement came two days after the rocker had a meltdown onstage at the iHeart Radio Music Festival in Las Vegas.
Armstrong became angry after the band was flashed a one-minute warning sign to wrap up the set on Friday. The front man stopped singing and delivered a profanity-laced tirade that was captured on a video that quickly went viral.
"You're going to give me one [expletive] minute? You've go to be [expletive] kidding me," he screamed. "It's a [expletive] joke!"
When the one minute ran out, the "American Idiot" singer smashed his guitar on the stage.
"Let me show you what one one [expletive] minute [expletive] means!" he said before flipping the middle finger and walking off stage.
The band issued a statement apologizing for Armstrong's outburst at the festival.
"We would like everyone to know that our set was not cut short by Clear Channel and to apologize to those we offended at the iHeartRadio Festival in Las Vegas," the statement said.
The band had to cancel some promotional appearances for their new album, "Uno," which was due to be released Tuesday.
Earlier this month, the singer was admitted to the hospital in Italy, forcing the band to cancel a concert in Bologna.
His band mates, Tre Cool and Mike Dirnt, released a short video apologizing to their fans.
"We apologize profusely, you know, this is really unfortunate, but Billie got rushed to the hospital last night due to illness, and the doctors don't think it's a good idea for him to play today," Dirnt says in the video.
"We're beyond devastated and sad," Cool adds, "Billie is extremely upset about it, and we'll see you soon."
Armstrong had reportedly been suffering from "gastric problems." No further information has been released about his condition.
The rocker is set to debut on season 3 of NBC's "The Voice" as a mentor on Christina Aguilera's team.
ABC News' Erin McLaughlin contributed to this report.