United Airlines on Friday became the latest carrier to raise the cost of checking a bag, as airlines grapple with a profit-crimping surge in fuel prices.

The fee to check a bag on the third-largest U.S. carrier on domestic, Caribbean and Central American flights booked Friday or later will cost $30, up $5. The move follows a similar change announced this week by JetBlue Airways. JetBlue also raised fees to change tickets, but United said it did not change any other fees.

Airlines have added or increased fees as more expensive jet fuel eats into their profits. They also have added new classes of no-frills service. U.S. jet fuel prices are about 20 percent more expensive than a year ago, according to S&P Global Platts.

The spotlight on baggage fees is now on American Airlines and Delta Air Lines, which recently started charging $60 for passengers on the cheapest class of service on trans-Atlantic routes to check a first bag. Delta and American did not comment on whether they would increase checked baggage fees for travelers on domestic routes.

Travelers paid U.S. airlines a record $4.6 billion to check bags last year, according to the U.S. Department of Transportation.