It was unclear whether the group of 12 Spaniards who fell prey to the attack had been targeted because of their nationality in the three-hour ordeal at a rented house on a tranquil beach dotted with restaurants, small hotels and rental homes. Most of the six men and six women live in Mexico City and were vacationing in Acapulco.
The five attackers burst into the house and held the group at gunpoint, said Acapulco Mayor Luis Walton. They tied up the six men with phone cords and bathing suit straps and then raped the six Spanish women.
Walton said the Spaniards had been "escorted," apparently under police protection, out of Acapulco on Tuesday.
Guerrero state Attorney General Martha Garzon told local media that the attackers' motive was "robbery, and to have fun," and they drank mescal they found at the house after committing the rapes. The lone Mexican woman, who's married to one of the Spaniards, "was saved by the fact that she is Mexican."
"She says she identified herself to the (attackers) and asked not to be raped, and they told her that she had passed the test by being Mexican and they didn't touch her," Garzon told Radio Formula.
Authorities and residents of Acapulco struggled to come to terms with the attack and its near-certain effect on the area's tourism industry, amid concerns that such violence could affect the draw of other, safer Mexican resorts.
Walton rushed to apologize Wednesday for his comment from Monday that "this happens everywhere in the world, not just in Acapulco or in Mexico."
"I apologize for having said that," he said Wednesday. "Of course this worries us and we don't want anything like this to happen in Acapulco or anywhere else in the world."
He added, "We know this is going to affect our tourism."
It's not clear how much interest there was in Acapulco among international tourists even before the Monday attacks, despite a major effort announced last year by business magnate Carlos Slim, the world's richest man, to rescue Acapulco by building parks and recreational centers.
Oceania and Regent Seven Seas Cruises, some of the last lines making port calls at Acapulco, cancelled them in December, the company confirmed.
The violence has included drug gang shootouts along the resort's main coastal boulevard and the dumping of severed heads on city streets.
But the early Monday attack exposed a security situation so bad that horrific violence was possible even in areas that appear relatively safe, like the laid-back stretch of beach southeast of the city's center where the Spaniards rented the house.
The manager of a small hotel near the house said he heard shouting during the attack just after midnight Monday, but did nothing because he felt it would be too dangerous. The man did want to give his name for safety reasons.
Other Mexican resorts continue to welcome tens of millions of international visitors every year, even as foreign tourism has largely vanished in Acapulco. Some feared the chilling effect of Monday's attack will be felt elsewhere.
"We are definitely not as contaminated with the crime issue as other states in Mexico," said Juan Carlos Gonzalez, tourism secretary of Quintana Roo, the Caribbean coast state where Cancun is located and which hosted about 17 million tourists last year. "We are really sorry about what happened with the Spanish tourists ... because in one way or another, it is something that affects Mexico's image."
"Apart from the illegal activities that occur between drug gangs, the idea that they would attack some tourist, that would hurt all the efforts we are making."
He said his state "certainly could have some cancellations, but given the number of Spanish tourists, it would not be significant."
Rafael Gallego Nadal, president of the Spanish Confederation of Travel Agencies, said the vast majority of the 50,000 Spaniards who head to Mexico every year travel to the Caribbean coast—and not to the Acapulco area that has been beset by drug violence for decades.
"This was a terrible attack but it's not the first time that something bad has happened in that part of Mexico. We Spaniards go to the Mexican Riviera" in and around Cancun, he said. "For us, this is an incredibly safe zone."
Gallego noted that most members of the group attacked are believed to be Spaniards living in Mexico City, and that Acapulco is a much bigger draw for domestic Mexican tourism than it is for international visitors.
Many Spaniards will go to Mexico during the long Easter Week vacation, and Gallego said he's heard no talk from travel agencies or groups about reducing package tour prices because of the rapes.
Kathy Gerhardt, a spokeswoman for Travel Leaders, a network of independently owned and operated travel agencies in the U.S., said events in Acapulco barely registers on U.S. tourists' radar anymore. "Those individuals trying to lump Acapulco into the list of top Mexico destinations U.S. travelers visit are misinformed. It has been decades since it was a hot tourist destination; today it is more of a destination for Mexican nationals rather than U.S. tourists."
In the group's recent survey of over 1,000 travel agency owner, managers and agents, "not a single individual chose Acapulco as a top international destination they are booking for their clients," Gerhardt wrote in an email, adding "we do not see any 'spillover effect'" for areas like Cancun, which Travel Leaders lists as the number-two foreign destination for U.S. travelers, after Caribbean island cruises.
Gallego said it's important for Mexican authorities to make arrests soon to prove that they can punish those responsible. Garzon, the state prosecutor, said "we have strong evidence to lead us to those responsible for this reprehensible act."
Acapulco is the granddaddy of Mexican resorts. Elizabeth Taylor was married there, John F. and Jackie Kennedy came on their honeymoon, and Howard Hughes spent his later years hiding out in a suite at the Princess Hotel, a pyramid-shaped icon in the exclusive Punta Diamante, or Diamond Point, zone.
Beheadings and drug gang shootouts, some on the city's main seaside boulevard, became more frequent after 2006, as gangs fought for control of the city's drug and extortion business.
Associated Press Writers Beth Harpaz and Alan Clendenning contributed to this report.