The 16-member Colombian-style music group was playing at a ranch in northern Mexico when at least 10 gunmen entered the warehouse where the private party was being held and forced them and four crew members into waiting vehicles, a survivor of the attack told authorities.
Nuevo Leon state security spokesman Jorge Domene said the survivor, a member of the Kombo Kolombia band, told police they were blindfolded and driven on dirt roads until they stopped and he heard gunshots and a conversation about where the assailants would dump the bodies.
Domene said the survivor, who is being protected by soldiers, was able to reach a nearby ranch and get help.
The man later led authorities to a well where searchers found several bodies, Domene said.
"Until yesterday, four bodies had been pulled (from the well) and all indicates that they belonged to this group," Domene told Radio Formula.
Domene said three of four bodies first pulled from the well were wearing T-shirt with the name of the band but that authorities were still waiting to officially identify them.
By Monday afternoon, searchers had pulled 10 bodies from the well along a dirt road in the town of Mina, about 140 miles (225 kilometers) from Laredo, Texas, said a forensic official, who spoke on condition of anonymity because he was not authorized to comment publicly on the case.
The bodies recovered showed signs of torture, the official said.
It was hard to determine how many more bodies were submersed in the water, he said.
Sixteen members of the band Kombo Kolombia and four crew members were reported missing early Friday after playing at a private party held at a ranch called La Carreta, or The Wagon, in the town of Hidalgo north of Monterrey.
People living near the ranch in Hidalgo reported hearing gunshots at about 4 a.m. Friday, followed by the sound of vehicles speeding away, said a separate source with the Nuevo Leon State Investigative Agency. He also spoke on condition of anonymity because he was not authorized to be quoted by the news media.
The officials added that gunfire is common in the area and said investigators found spent bullets nearby.
Relatives filed a missing persons report on Friday after losing cellular phone contact with the musicians. When they went to the ranch to investigate, they found the band members' vehicles still parked outside.
Kombo Kolombia has played a Colombian style of music known as vallenato, which is popular in working class neighborhood in the city of Monterrey and other parts of Nuevo Leon state. Most of the group's musicians were from the area, though the singer is a Colombian citizen with Mexican residency, Domene said.
The band regularly played at bars in downtown Monterrey on the weekend. At least two of the bars where they had played had been attacked by gunmen.
It was Mexico's largest single kidnapping since 20 tourists from the western state of Michoacan were abducted in Acapulco in 2010. Most of their bodies were found a month later in a mass grave. Authorities said the tourists were mistaken for cartel members.
Members of other musical groups have been murdered in Mexico in recent years, usually groups that perform "narcocorridos" that celebrate the exploits of drug traffickers. But Kombo Kolombia did not play that type of music, and its lyrics were about love and heartbreak and did not deal with violence or drug trafficking.
But singers of drug exploits are not the only musicians targeted, said Elijah Wald, author of the book, "Narcocorrido: A Journey into the Music of Drugs, Guns and Guerrillas."
"There is really not correlation. Drug guys hire people to play for their parties and they hire whatever is happening," he said. "Sergio Gomez, the single-most famous singer killed from K-Paz de la Sierra, his big hit was a version of 'Jambalaya.'"
Gomez was kidnapped and found strangled and tortured in 2007 in the western state of Michoacan, a day after Zayda Pena of the group Zayda and the Guilty Ones was shot in a hospital while recovering from a separate bullet wound in the border town of Matamoros, across from Brownsville, Texas.
Valentin Elizalde, "El Gallo de Oro," was shot to death along with his manager and driver in 2006 following a performance in Reynosa, across the border from McAllen, Texas. Norteno singer Sergio Vega was shot dead in a northern state of Sinaloa in 2010.
"A lot of people are being killed because they're in the wrong place at the wrong time and musicians are some of the people on that list," Wald said.