Kings of Leon announced the cancellation of their U.S. tour following an onstage meltdown at a performance in Dallas on Friday night (July 29). Frontman Caleb Followill walked offstage after claiming he was too hot to perform, and the band subsequently postponed its show in Houston scheduled for the following night.

"We are so sorry to say Kings of Leon are canceling their entire US tour due to Caleb Followill suffering from vocal issues and exhaustion," reads a statement from the band's publicist. "The band is devastated, but in order to give their fans the shows they deserve, they need to take this break."

The statement also says that the 28 dates "cannot be rescheduled due to the band's international tour schedule. Tickets will be refunded at point of purchase. Tickets purchased online or via phones will be automatically refunded. The band will resume touring in Canada at the Rogers Center in Vancouver, BC, on September 28th. That show was originally schedule for September 14th."

Kings of Leon Concert Cut Short, Another Nixed; Bassist Admits 'Problems in Band'

The tour was scheduled to make a swing throughout the Southeast this week, starting with Tampa on Tuesday (Aug. 2) and winding through West Palm Beach (Aug. 3), Charlotte (Aug. 5) and Virginia Beach (Aug. 6) before heading up to the Northeast.

So far, the band's response to the scrapped tour comes from Twitter and, understandably, they're not very happy about it.

"Utterly depressed. It's completely out of my hands. Family has to come 1st. If bass solos & backing vocals were more popular, I'd be there," bassist Jared Followill wrote. "Thanks to all my friends, family, & fans. I'm not going to stop working. I'm going to spend time writing songs and looking to the future."

Nathan Followill, drummer and the band's elder, followed that up by insisting the band was simply taking a break. "We just need some rest," he said. "Thanks 4 understanding. WE ARE NOT BREAKING UP!"

During Friday's Dallas show, Caleb Followill told fans at the Gexa Energy Pavilion that his voice was "100 percent gone" due to the heat. "I'm gonna go backstage and I'm gonna vomit, I'm gonna drink a beer and I'm gonna come back out and play three more songs," Followill told the crowd before leaving the stage for good.

A statement from the group chalked up Friday's meltdown to "heat exhaustion and dehydration… causing [Followill's] vocal chords to seize." However, the rest of the group's reaction to the incident has hinted at the band's internal problems: drummer Nathan Followill called the show a "fiasco" on Twitter, and bassist Jared Followill wrote, "I know you guys aren't stupid. I can't lie. There are problems in our band bigger than not drinking enough Gatorade."

The group originally rescheduled the Dallas and Houston shows for Sept. 21 and Sept. 22, but those dates are now cancelled.

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Kings of Leon have been on the road supporting their fifth album, "Come Around Sundown," which has sold 640,000 copies since its release last October, according to Nielsen SoundScan. The group is scheduled to tour Canada this fall before heading to Australia in November.

NEXT: See the Full List of Canceled Dates