Ecuador ? One of two known survivors of a drug gang’s massacre in northern Mexico of 72 undocumented Central and South American migrants said in an interview broadcast Thursday that they were killed because they refused to work for the traffickers.

He also urged others not to attempt the journey to the United States.

Luis Freddy Lala Pomavilla, 18, said the migrants — 76 in all — were seized after they entered Mexico from Guatemala.

He described being held one night, bound in groups of four, before the gunmen shot all the migrants.

“I’m telling everyone, Ecuadoreans, don’t make the journey any more because the Zetas are killing a lot of people,” Lala said, referring to the drug gang that dominates parts of Tamaulipas state, where he was found last week.

Lala, who was wounded in the neck, wore a brace and part of his face was bandaged. His speech was labored in a two-part interview broadcast by state-run GamaTV.

“There are a lot of bad people who won’t let you through,” he said in the interview, which was apparently recorded during his plane flight home from Mexico on Sunday.

He said the migrants, mostly male and including Ecuadoreans, Salvadorans, Hondurans, Guatemalans and a Brazilian, were killed because they refused to work for the Zetas.

“They didn’t ask us for anything but only said, ‘You want to work with us?’ And nobody wanted to work with them,” Lala said.