American Airlines said Thursday night that it increased most domestic and U.S.-Canada fares by $5 one way and $10 round-trip, effective immediately.

"The increase is to help offset the continuing high cost of jet fuel," American said. It's the latest move by airlines to try raising fares to cover fuel costs. "Each $1 rise in the price per barrel of crude oil costs American Airlines approximately $80 million a year," the airline said.

It was not clear whether other carriers would follow suit with price increases.