OAXACA/SAN SALVADOR,Mexico - Armed men kidnapped about 50 Central American migrants in southern Mexico after holding up the cargo train they were riding on, El Salvador's foreign ministry said on Tuesday.

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A local priest who runs a shelter for migrants said witnesses reported that women and children were among those abducted on the night of December 16, and not seen since.

"Witnesses said that the subjects climbed up on the wagons, struck the migrants with machetes and took their belongings," El Salvador's foreign ministry said in a statement. "Afterwards they took away all the women traveling on the train."

In August, hitmen believed to be from the brutal Zetas drug gang kidnapped and killed 72 migrants at a ranch near the US border. The victims were blindfolded and bound before being lined up against a wall and gunned down, authorities said.

Priest Alejandro Solalinde, who runs the "Hermanos en el Camino" (Brothers on the Way) shelter in the town of Ixtepec in the southern state of Oaxaca, said he suspected the Zetas were behind the latest abduction as well.

Solalinde said 17 people who had also been traveling on the northbound train arrived at the hostel on December 17 and said the migrants were abducted in Chahuites, about 300 km (186 miles) from the border with Guatemala.

"Fourteen witnesses stayed in the shelter, and yesterday and the day before someone came to ask that they be handed over to the Zetas," he said. Authorities had since removed the witnesses to a safe location, he said.

'No evidence'

El Salvador's foreign ministry said it condemned acts of aggression against migrants traveling through Mexico to the United States.

"The foreign ministry demands that the Mexican government investigate this," the ministry said in a statement.

But Mexico's interior ministry said it had found no evidence backing claims of the disappearance.

The nationality of those kidnapped was not immediately clear, although Solalinde said they included one woman from Honduras and three women from Nicaragua. Honduras has also asked Mexico for information about the case.

Some migrants pay as much as $10,000 to smugglers who promise to get them into the United States. Many others see their journeys end in robbery, assault or arrest. Women often report rapes during the voyage, and some have been forced into prostitution.

Corrupt Mexican police are often accused of playing a role, turning illegal migrants over to drug gangs for a price.

Countless Latin American migrants journey some 3,000 km (1,900 miles) through Mexico hoping for a better life in the United States, some clinging to the top of cargo trains or hiding in secret compartments built into tractor trailers.