MEXICO CITY — As a group of mothers from Honduras, Guatemala and other countries travels across Mexico in search of missing relatives, the Mexican navy on Monday announced that it had freed 14 Central Americans kidnapped by suspected drug traffickers.

Thousands of migrants from Central America go missing every year as they attempt to reach the United States through Mexico. They are often kidnapped by Mexican gangsters, held for ransom, forced to work for cartels or on marijuana farms, or killed. Many turn up in hidden mass graves.

Naval marines acting on what they described as an anonymous tip over the weekend discovered 14 migrants being held against their will in a shack in the town of Altamira, in the violent border state of Tamaulipas. The state has been the scene of several massacres of Central American and Mexican migrants.