Two weeks later, there has been no trace of the men. Investigators have yet to announce any good leads, even though two others from the group were not taken.

Against the backdrop of Mexico's extraordinary drug violence, it's tempting to write off the Sept. 30 disappearance as another grim skirmish between rival traffickers. Group kidnappings have been a common feature of the feuding, though generally with fewer victims.

But in the Acapulco case, the pieces don't add up neatly.

Relatives back in the western state of Michoacan insist they were no drug henchmen, but ordinary guys: mechanics, students, deliverymen, an accountant, a physician. Loved ones said the friends and co-workers saved up for months for an annual, guys-only weekend in the seaside resort.

"None of them had any ties or relationship with any group that is involved in illicit acts … and had no conflicts with anyone, or threats of any kind," the relatives said in a joint statement issued shortly after the men disappeared.

Family members listed the men's names and ages — 17 to 58 — and jobs. Nine of the missing worked in the same wheel-alignment shop in Michoacan.

Still, it's hard to explain why 20 law-abiding men would be seized at gunpoint on the way to beach-side relaxation. Authorities have made comments casting doubt that the men were mere tourists, but have not specified a motive for the disappearances.

The outcome of the mystery matters to Acapulco, which is struggling to recover some of its former cachet and can hardly afford the image of gunmen seizing innocent visitors.

Sensitive to the effect of violence on the country's crucial tourism industry, Mexican officials have said the rising bloodshed nationwide is not aimed at travelers. That has been largely true: Even though drug-related violence has killed more than 300 people in and around Acapulco since 2006, for instance, most of it has been far from the main tourist zone.

The missing men arrived in four cars from Michoacan, itself a violent, drug-trafficking hot spot, and were apparently heading to or hunting for a hotel when seized. The kidnappings were reported by one of two members of the group who had split off to go to the store when the others were taken.

A state police commander first raised an eyebrow, saying it was unusual for a group of men to go on vacation without family members. And Zeferino Torreblanca Galindo, governor of the state of Guerrero, where Acapulco is located, was also quick to express skepticism.

"We assume it has to do with organized crime," Torreblanca said a day after the news broke. "I don't think anyone comes to deliberately carry out an attack on 20 tourists."

When the families complained that officials appeared to be blaming the victims, the authorities backed off, announcing that checks showed that none of the missing men had criminal records.

When the men's vehicles were recovered, investigators found signs of a road trip — suitcases, beer, cookies — but no weapons or contraband.

But last week, Mexico's tourism minister, Gloria Guevara, reignited tensions when she said the missing men "didn't fit the usual profile" of a tourist.

"A tourist usually travels with family, has a hotel reservation, arrives directly at his hotel and fits certain profiles," she told a congressional committee when a question about the case came up. Guevara stopped short of tying the men to criminal activities, but the implication seemed clear.

Families of the men fired back, accusing Guevara of a "lack of responsibility" and offering papers showing the group had reserved rooms for the three-day stay in a hotel they did not publicly identify.

"We're very worried about our family members because we don't know anything about them, and now we are angry that [officials] keep insisting that they weren't tourists," a relative who identified herself only by her first name, Katia, said during a radio interview.

Early this year, President Felipe Calderon came under fire and apologized to grieving survivors in Ciudad Juarez after he initially said gang revenge was behind a fatal shooting attack that killed 15 people at a teen party. It turned out that none of the victims had anything to do with gangs.

The Michoacan families say they don't want the mystery of the missing men to be brushed aside. "What we want is to have news about them and for our suffering to end," Katia said.

On Wednesday, Guerrero's state prosecutor, David Augusto Sotelo, announced that investigators were following two possible leads. But he refused to say what they were.

ken.ellingwood@latimes.com