United Airlines is also raising its checked bag fee. See by how much.

Two major U.S. airlines announced higher fees for air passengers in one week.

United Airlines announced Friday it will be raising its checked bag fee for customers traveling in the U.S. by $5 starting Saturday, following American Airlines' announcement.

Passengers will pay $40 for their first checked bag ($35 by paying in advance) and $50 for a second checked bag (or $45 in advance).

"For the first time in four years, United is raising checked bag fees for customers traveling in North America," United said in a statement. "United Chase credit card holders, MileagePlus Premier members, active military members and customers traveling in premium cabins can still check a bag for free, and customers in most markets will still enjoy a $5 discount if they prepay for their bags online at least 24 hours before their flight."

The airline said it is in the process of updating all of its mainline aircraft to fit more carry-on bags.

American Airlines announced earlier this week it was raising the price of a first checked bag from $30 to $40 on most flights – or $35 by paying in advance – pointing to the price of fuel as a major factor in the increase.

JetBlue and Alaska Airlines also raised bag fees this year.

This article originally appeared on USA TODAY: United Airlines checked bag fee increase: What to know