Police detained 42 undocumented migrants who were traveling in two buses through northeastern Mexico in a bid to reach the United States, the Public Safety Secretariat said.

The migrants were taken into custody at two separate checkpoints set up on highways in the country's northeast.

The first detentions took place on the Nuevo Laredo-Piedras Negras highway in Tamaulipas state, where Federal Police stopped a bus carrying 21 Guatemalans and a Honduran woman.

The undocumented migrants identified one of the passengers, 24-year-old Santiago del Carmen Ramirez Toga, as the person smuggling them to the border, and he and driver Manuel Santoyo Rodriguez were turned over to federal prosecutors.

Meanwhile, Federal Police discovered 20 other illegal migrants - 16 Hondurans and four Salvadorans - in another bus in San Roberto, a town in the neighboring state of Nuevo Leon. The migrants were handed over to federal immigration authorities in Saltillo, capital of the northern state of Coahuila.

That operation on the Matehuala-Saltillo highway was carried out jointly by Federal Police and immigration authorities.

"The human rights of these people were respected at all times and they were provided food and medical attention to ensure their wellbeing," the secretariat said.

Tens of thousands of undocumented migrants, mostly Central Americans, traverse Mexican territory every year in their attempt to reach the United States.

Illegal immigrants face a dangerous journey in which they must pay people smugglers and avoid falling into the hands of organized crime gangs or corrupt authorities.