Mexican soldiers found 140 migrants inside a truck in the state of Chiapas near the Guatemalan border.

The truck was originally stopped by authorities who were looking for drugs. They found a false wall in the back of the tractor-trailer where the migrants were hiding, according to the BBC. The group was made up of 128 men and 12 women, all claiming to be from Guatemala.

Two men were detained in connection to the migrants.

Last year, Mexican authorities discovered 25,000 illegal immigrants in the country. Hundreds of thousands more travel from Central and South America through Chiapas, most aiming for the U.S.

However, in an unrelated development, the net immigration rate between the U.S. and Mexico is beginning to reverse. The stalled U.S. economy is sending both documented and undocumented migrants back to their home countries, according to the Los Angeles Times.

U.S. Border Patrol arrested 304,755 people crossing the southwest border in that last 11 months, a significant drop compared to the 1.6 million arrests made in 2000.

We are at a new point in the history of migration between Mexico and the United States, Douglas Massey, an immigration scholar at Princeton University, said at a Mexico City press conference.

Unemployment in the U.S. and frightening drug violence in Mexico is dissuading many Central Americans from making the trip north.