PHILADELPHIA: Air travel in the United States hit another pandemic-era record over the weekend as vacationers jammed airports, but shares of airlines, cruise lines, hotels and almost anything else related to travel tumbled on Monday on growing concerns about highly contagious coronavirus variants.

The Transportation Security Administration (TSA) said it screened more than 2.2 million people at airport checkpoints on Sunday, the highest number since early March 2020 when the pandemic was beginning to crush travel in the United States.

That topped a record set just two days earlier and was the fourth peak recorded in July. However, Sunday's mark was still 18 percent lower than on the comparable Sunday in 2019, according to the TSA.

But investors weren't celebrating the latest evidence of a recovery in travel since vaccines against Covid-19 became widely available in the US Stocks fell broadly - the Dow Jones Industrial Average lost 2.1 percent - on concern about rising infections in many countries, and airline and cruise line stocks were hit especially hard.

United Airlines shares tumbled 5.5 percent, American Airlines and Delta Air Lines each fell about 4 percent, and Southwest dipped nearly 3 percent.

Cruise line stocks fell to levels last seen before vaccines were widely available to Americans. Carnival, Royal Caribbean and Norwegian Cruise Line Holdings each lost between 4 percent and 6 percent. Hotels and Airbnb also slipped.

Shares of Boeing, which is just starting to see a recovery in aircraft orders, fell 5 percent. Tensions rose on Monday between the United States and China - a huge market for planes and one that has not lifted its grounding of Boeing 737 Max jets - when the US and allies formally blamed China for a major hacking attack.

Airlines said domestic leisure travel is back to pre-pandemic levels but international travel and business trips both remain sharply lower than in 2019. That is especially bad for American, United and Delta, which get a sizable chunk of revenue from international and business travel.

Airlines are frustrated that restrictions on international travel haven't been relaxed more quickly. The rise in coronavirus infections - the US daily rate of new reported cases has more than doubled over the past two weeks and the World Health Organization said the Delta variant is causing cases and deaths from Covid-19 to rise worldwide after a period of decline - could delay moves to make travel easier.

After massive losses last year, airlines are doing better with more Americans booking flights. Delta reported a second-quarter profit last week, thanks to federal pandemic relief. United, American and Southwest report results this week.