MEXICO CITY (AP) — The U.S. Treasury Department announced sanctions Thursday on a man from Sierra Leone for allegedly smuggling thousands of migrants from Asia and Africa into the United States.

The ring allegedly run by Abdul Karim Conteh provided false documents and drove migrants to the border and offered advice on how to cross, the Treasury said. It also allegedly also moved some migrants through Nicaragua, the Central American country which has been used as a springboard for migrant smuggling because of its lax visa requirements.

The smuggling ring's customers came from a dozen countries, including China, Iran, Russia, Somalia, Afghanistan, Pakistan and Nigeria.

Karim Conteh was arrested on July 11 in Tijuana, Mexico. The United States is pursuing Conteh’s extradition on federal migrant smuggling charges.

Also sanctioned Thursday was his Mexican wife, Veronica Roblero, as well as two other people from Sierra Leone and Togo.

The department’s Office of Foreign Assets Control, or OFAC — the U.S. agency that combats illicit funds and money laundering — said the ring allegedly moved the money they charged the migrants for helping them cross the border illegally through the United States.

The sanctions block the targets' financial and other assets in the United States and prohibit U.S. citizens from having any transactions with them.