DALLAS (AP) — Even as the deaths of 10 immigrants found in the back of a sweltering tractor-trailer in Texas have captured international attention, the deaths of five others who drowned this week while trying to get into the U.S. by swimming across the Rio Grande have largely gone unnoticed.

The latest death was discovered Thursday, when U.S. Border Patrol agents conducting a river patrol with Mexican law enforcement officials found the body of a man believed to be in his 30s. The bodies of three people, all Guatemalan nationals, were recovered Tuesday. Another person who was pulled from the water this week later died at a hospital.

The number of deaths is unusual for the Border Patrol's El Paso sector, which extends from the Arizona border to the west down to just southeast of El Paso in Texas. Three water-related deaths were reported there during the last fiscal year, compared with eight so far this year, according to Border Patrol spokesman Joe Reyes. Meanwhile, the number of people apprehended while attempting to enter the U.S. illegally in that sector has dropped slightly.

Officials say at least 15 people have attempted to cross the river in the same area this week. The five deaths reflect some of the hazards immigrants may face when trying to enter the U.S. illegally.

Reyes said the difference this year for people trying to cross the Rio Grande is more rainfall than usual that's resulted in elevated water levels. Heavy rain that began Sunday had pushed the river water nearly 2 feet higher than normal and produced an undercurrent that moved about 25 mph.

"We haven't seen it this bad in the last few years," Reyes said.

Border Patrol has distributed Spanish-language public service announcements to Mexican media warning of the dangers of crossing the border, he said. The announcements also are played in U.S. detention centers.

Investigators believe the case involving the tractor-trailer found Sunday in a Walmart parking lot in San Antonio may involve a larger organization involved in human smuggling. Dozens of immigrants were pulled from the rig. Ten died, while others were treated for extreme dehydration and heatstroke.

Heat is a hazard immigrants can face when crossing on foot as well. Federal officers regularly find the bodies of migrants, one or two at a time, who succumb to heat or exposure in the remote landscape of western or southern Texas.

Many of the bodies go unclaimed, resulting in their burial in unmarked graves in Texas cemeteries.

Javier Prieto, a Border Patrol spokesman southeast of El Paso in the Big Bend sector, said those whose bodies have been found in isolation likely were not traveling alone.

"If there's a group and one or two are not feeling well or aren't strong enough to make it across or they get hurt or become sick, usually they get left behind, unfortunately," Prieto said.

___

Follow David Warren on Twitter at https://twitter.com/WarrenJourno