Airlines are scaling back service to Mexican resort cities after a recent drop in bookings following reports of violence and tourists blacking out after consuming small amounts of alcohol.

Travelers at resorts in cities such as Cancun and Playa del Carmen have reported blacking out — some after only having one drink — only to wake up to find they had been robbed or assaulted, according to an investigation by the Milwaukee Journal Sentinel that spanned more than a year.

Some tourists suspect they were drugged or given tainted alcohol. Some have even died.

While they didn't single out violence or the blackouts as a cause, airlines such as United, Delta, American and Spirit said in quarterly earnings calls that they saw decreased demand for travel to Mexico. Several said they have or will consider trimming flights offered to Mexican resort areas, the Journal Sentinel reported.

American Airlines, headquartered in Fort Worth, said the company's business in Latin America was doing well, "with the exception of Mexico pleasure markets," president Robert Isom said in a transcript of the call.

Spirit Airlines singled out Cancun as a destination where customers are unwilling to pay the higher prices to travel there that they once did.

"There's been a lot of travel advisories for Cancun and other Mexican destinations," Spirit's chief commercial officer, Matt Klein, said in a transcript of the earnings call. "But, for us, the most impactful is Cancun for sure. And those travel advisories have been out there all year."

The U.S. Department of State hasn't restricted travel to Quintana Roo, the state where tourist areas such as Cancun, Playa del Carmen and Cozumel are located. But a July 2018 travel advisory warns travelers that the state has seen an increase in homicide rates.

In a particularly bloody stretch in April, 14 people were reported killed in Cancun in 36 hours near tourist attractions. Later that month, five bodies were found stuffed in a car.

U.S. officials say most of the homicides are "targeted, criminal organization assassinations," but sometimes violent crime affects tourists. "Shooting incidents injuring or killing bystanders have occurred," the State Department's advisory for Quintana Roo says.