The government has fined American Airlines and Delta Air Lines for several instances where passengers were stuck on planes that spent over three hours on airport tarmacs.

The Department of Transportation said Thursday it is fining American $1 million and Delta $750,000 for violating rules prohibiting tarmac delays of more than three hours for domestic flights and four hours for international trips.

The agency said that 13 flights operated by American at various U.S. airports between December 2015 and January 2017 violated its tarmac-delay rules. Delta was dinged for 11 flights between January 2017 and February 2018.

American will be credited $450,000 for compensation provided to passengers and Delta will be credited $450,000.

(AP)