Authorities in the US state of Texas have urged Americans to avoid visiting Mexico for spring break because of security concerns.
Drug cartel violence, according to the Texas Department of Public Safety (DPS), poses a serious concern to anyone entering Mexico.
The travel advisory follows the kidnapping of four Americans last week just after they crossed the border.
Two of them were killed, and the other two were let go uninjured.
More than two weeks have passed since the disappearance of three American women who traveled to Mexico to sell clothing at a market.
“Drug cartel violence and other criminal activity represent a significant safety threat to anyone who crosses into Mexico right now,” said DPS director Steven McCraw.
“Based on the volatile nature of cartel activity and the violence we are seeing there, we are urging individuals to avoid travel to Mexico at this time.”
A drug gang abducted four Americans and killed two of them in the Mexican town of Matamoros earlier this month. A Mexican onlooker was also shot dead.
The cartel who committed the crime has since issued an apology and turned over its own shooters to the authorities.
A note left with the cartel gunmen, who had been left on the roadside, accused them of acting “under their own decision-making and lack of discipline” as well as apparently disregarding cartel norms over “saving the lives of the innocent”.
The letter was signed by the “Scorpions Group,” a breakaway group from the formidable Gulf Cartel.
According to Mexican authorities, the gang members shot at the Americans when they attempted to flee because they thought they were competitors.
The event might deteriorate ties between the two nations.
The administration of President Joe Biden has been pushed by a Republican senator to permit the deployment of American troops across the border to combat the cartels.
The suggestions were labeled “arrogant” by Mexican President Andrés Manuel López Obrador.
According to US authorities, two sisters from Texas and a friend who crossed the border last month to sell clothes at a flea market are currently missing in Mexico.
As several days passed with no updates, the husband of one of the women called Texas police to report his wife’s abduction.
“We don’t know if they made it there,” Roel Bermea, police chief in the border town of Penitas, told the AFP news agency. The FBI had been notified, he added.