Three alleged drug traffickers, including two who live in the city, remain at large, officials said. View Full Caption Shutterstock/file photo

CHICAGO — A sweeping federal crackdown targeting wholesale drug dealers on the city's Northwest Side and suburbs racked up 10 arrests and more than 200 pounds of confiscated heroin, cocaine and fentanyl, U.S. attorneys announced Thursday.

During an investigation starting in 2015, FBI and DEA agents used "extensive undercover surveillance" to track illegal drug sales of up to $54,000 each in Belmont Cragin and nearby suburbs, according to the announcement.

Drug trafficking charges were filed against 13 people, prosecutors said. Five were arrested earlier this year and another five were arrested on Wednesday, leaving three who are "considered fugitives ... being sought by law enforcement," officials said.

Two of the fugitives, Javier Moreno and Pedro Saavedra-Fitz, are both listed as city residents. Prosecutors allege that the men sold smaller packages of drugs to wholesale buyers on credit, then collected proceeds after the customers sold the drugs, in a practice known as "fronting."

Detention hearings for the five men arrested on Wednesday will be held on Friday and next week.