Authorities detained two buses carrying 102 migrants from African nations in the southern Mexican state of Oaxaca on Tuesday morning, according to Mexico’s immigration agency.

Three suspected people smugglers traveling with the convoy were also arrested.

The majority of the migrants came from the West African nations of Senegal and Guinea, as well as six from Djibouti, two from Congo and one from Mauritania.

20,000 MIGRANTS APPREHENDED OVER THE WEEKEND, INCLUDING SEX OFFENDERS AND GANG MEMBERS

Authorities did not say how the migrants are thought to have arrived in Mexico, but African migrants have been known to use Nicaragua as a transit point to reach the U.S., because of the country's lax visa requirements.

In the past month Mexican authorities have claimed to "rescue" or "locate" hundreds of migrants from houses, vehicles, and a trailer box. With a few exceptions, experts said the rescues are more accurately characterized as arrests.

"They are almost 100% apprehensions," said Ari Sawyer, a border researcher at Human Rights Watch, who likened the wording used by Mexican authorities with that of the U.S. Customs and Border Patrol.

Mexico’s immigration agency said Tuesday in a news release that the detained migrants were being processed in Oaxaca, but did not say if Mexico would attempt to return them to Africa.

Earlier this month an internal memo seen by The Associated Press showed that the agency cannot afford to deport or transfer any more migrants after a record-setting year for migration.