American Airlines just increased one-way costs on domestic flights by $ 5. The airline confirmed the price increase in an email to CNN Business.
The increase was observed earlier on Thursday by JPMorgan analyst Jamie Baker, who added in a survey that it was found that Hawaiian Airlines has been following US leadership by increasing prices across the system.
Baker also noted that Southwest raised prices on several flights, especially for business travelers.
Southwest matched US price increase in some markets, but the airline told CNN Business on Thursday that it did not "cross the board in a market."
Hawaiian was not immediately available for comment on the reported car prices.
The news of higher prices seems to have surprised investors, mainly because it has been less than a month since the recent industry's price increase.
"We didn't expect another increase so soon," Baker wrote in his report. He added that because fuel costs have come down to late, "we were obsessed with domestic prices much less than usual given what we saw as a low probability of further increases."