(NewsNation) — As fentanyl continues to kill Americans at record numbers, the U.S. Drug Enforcement Administration is focusing on the splinter cartel group “Los Chapitos,” run by the sons of infamous drug lord El Chapo.

The group is now playing a massive role in the drug trafficking business for the Sinaloa Cartel.

Los Chapitos introduced fentanyl to the Sinaloa Cartel, helping them establish relationships with Chinese criminals who would ship the ingredients needed to make the drug from Asia to Mexico, according to federal officials.

Since then, Los Chapitos have become experts in getting fentanyl moved across the border and into American cities all over the country.

Now, the DEA is adding three of Los Chapitos’ top operatives to the country’s most wanted drug dealers list.

At the top of that list is Oscar Noe Medina Gonzalez, the right-hand man to one of the sons of El Chapo. Medina Gonzalez is a seasoned hitman and is charged with protecting the fentanyl export routes and assassinating rivals from other Mexican cartels. He also expanded drug-trafficking territory and coordinated attacks against Mexican law enforcement.

The U.S. government is offering $4 million to anyone who can assist in his capture.

Second on the new most-wanted list, is Kun Jiang, a Chinese citizen who supplies the Sinaloa Cartel with chemicals used for making fentanyl. His arrest presents a challenge for federal officials as they don’t have an extradition agreement with China. Jiang has a $1 million bounty on his head.

Finally, federal officials are looking for Luis Javier Benitez Espinoza, one of the main fentanyl traffickers for the Sinaloa Cartel. According to officials, he has trafficked thousands of fentanyl doses into the U.S. through San Diego and is under the direct order of Los Chapitos.