Mexican officials will install health checkpoints at various entry points along its northern border this weekend, as both Mexican and U.S. officials fear a surge of crossings for the July 4 holiday could spread the coronavirus.

Mexican consulates across the United States in recent days reiterated warnings on social media of the ramped-up measures scheduled for July 2 through July 5, and urged people to refrain from crossing for recreation or tourism.

A ban on non-essential border travel has been in place since March in an attempt by both governments to limit coronavirus infections, yet cross-border traffic has been busy.

Mexico’s northern border region is home to a large population of green card holders and U.S. citizens, including dual nationals, who are typically free to cross back and forth.

In Sonora, which has Mexico’s third-highest coronavirus rate per capita and sits opposite Arizona, Governor Claudia Pavlovich said health screenings would span beaches and towns frequented by Mexicans and tourists.

Neighboring Baja California, including the bustling border city of Tijuana across from San Diego, ranks fifth for most coronavirus cases per capita.

Chihuahua, Coahuila, Nuevo Leon and Tamaulipas states have each registered at least several thousand confirmed cases, and all sit opposite Texas, which is grappling with a surge in infections including a record number of hospitalizations on Friday.

U.S. Ambassador Christopher Landau on Saturday urged people to celebrate the holiday virtually in a video posted on his Twitter account that featured a member of the pop band the Backstreet Boys and entertainer Steve Aoki, among others.

He had already urged people to stay put in one country or the other over the Independence Day weekend. Hundreds of thousands of people cross by land per day despite the ban on non-essential travel, he said.

“If U.S. citizens continue to make casual cross-border trips, the restrictions will increase, not decrease,” Landau wrote on Twitter.

“Whichever side of the border you live on, this is NOT the time to cross to shop, eat, or visit family on the other side.”

Even so, photos posted on social media on Friday showed long lines of cars in the border city Nogales in the northern state of Sonora seeking to cross into Arizona.

Reuters