(Cover) - EN Showbiz - Jared Followill has admitted there are "problems" in Kings of Leon.

The American rock band, comprising of brothers Caleb, Nathan and Jared Followill and their cousin Matthew, have been hitting the headlines after a series of concerts were postponed and another was cancelled this weekend.

Controversy was sparked on Friday when singer Caleb left the stage in Dallas with three songs still remaining to be played.

"I'm trying to sing but I haven't got a voice, I've got nothing," he said at the time.

The rockers then pulled out of a show in Houston, Texas, the following night. According to the band's representative Caleb was suffering from "heat exhaustion and dehydration" which had caused his "vocal chords to seize".

Jared has expressed his fears about the band on social-networking site Twitter, hinting that the issues run deeper.

"I know you guys aren't stupid. I can't lie. There are problems in our band bigger than not drinking enough Gatorade (sic)," he wrote.

Kings of Leon have rescheduled their concert at the Cynthia Woods Mitchell Pavilion in Texas for September. Meanwhile, their US tour is expected to continue in Tampa, Florida on August 2. (C) Cover Media