SOUTH PADRE ISLAND, Texas — Michigan State senior Paul Bonenberger avoided temptation during this island's season for wild spring break partying by leaving his passport at home.

"I've heard tons of (stuff) about the border," said Bonenberger, 21, two beers in hand and surrounded by hundreds of Midwestern spring breakers on the beach. "I've heard it's unsafe. I'm not about the border anymore, it's not worth the risk."

Once, most South Padre spring breakers visited nearby Matamoros, Mexico, for the touted "Two-Nation Vacation."

But news of gunbattles between soldiers and drug cartels in Mexican border cities this winter appears to have reached even the frigid campuses of the upper Midwest. Tourists have not been targeted, but students and tourism officials on both sides of the border say spring breakers are keeping their toes in U.S. sand this year.

The young, tan masses have not been surveyed lately, but Dan Quandt, executive director of the island's convention and visitors' bureau, said, "We have noticed over the past few years a decline in the number of students going to Matamoros."

Debra Fassold, who manages a cross-border shuttle service, said she used to ferry several hundred spring breakers daily and now gets only a few dozen. She has canceled night trips.

"I've had no reason to schedule them this year," Fassold said.

Those partying on South Padre Island said they opted to stay domestic this year not just because of safety concerns, but also because of tighter identification demands for returning to the U.S.

Rachel Padgett, of Austin, has been coming to South Padre Island for more than half her life. It was traditional to go over to Matamoros for a haircut and to shop for jewelry, but not this year, said the 21-year-old Michigan State student.

"Not right now. There's a drug war," Padgett said.

Students from the University of Texas and Texas A&M descend on South Padre this week, the apex of spring break on the island off the coast of South Texas.

Matamoros and other border cities in Mexico are now patrolled by Mexican soldiers sent to the border to quell drug cartel violence. Their armored personnel carriers and machine guns are far from inviting.

Arturo Morales, tourism promotion director for Matamoros, said the military is there to protect residents and tourists.

Morales said fewer spring breakers were visiting the city across the Rio Grande from Brownsville, but said spring breakers need to learn more about the military's security role. Morales noted Winter Texans — northerners who spend the winter in Texas and then return home in the spring — have become accustomed to the military presence and continue visiting border cities.

Some students have crossed the border without worry. Joseph Cook and Ariela Ruiz, students at Evangel University in Missouri, enjoyed a day of shopping and sight-seeing on the recommendation of their hotel concierge.

They drove to Brownsville, walked across the bridge and took a taxi to Matamoros' main market area. They saw federal soldiers stopping and checking cars, but had no problems.

Asked if anyone had warned them about going to Mexico, Cook said: "Just my parents. They said, 'Be careful.' "