PHOENIX — More than 150 passengers were forced to sweat it out on an Allegiant Airlines plane for 2 1/2 hours after a maintenance issue left the aircraft without air conditioning.

KTVK-TV reports (http://bit.ly/1bttn5b) passengers had already boarded the plane at Phoenix-Mesa Gateway Airport on Wednesday when the issue was discovered. The station says passengers were required to stay in their seats in triple-digit temperatures even though the plane was still at the gate.

There were no reports of any injuries to the passengers, and it isn't immediately clear where the delayed flight was headed.

A call Friday to Las Vegas-based Allegiant for comment wasn't immediately returned. The airline has said Arizona's summer heat can increase mechanical issues.

Allegiant offers nonstop service from many small towns around the country to popular destinations in Arizona, Nevada, Florida, Hawaii and elsewhere.