(NewsNation) — More than 550,000 pounds of illegal drugs have been seized at the U.S.-Mexico border this year, including a 200% increase in the amount of fentanyl encountered by U.S. authorities.

In Tucson, Arizona authorities have seized 370,000 illegal fentanyl pills. The increase in drug seizures is one of the reasons Arizona Gov. Doug Ducey is constructing a makeshift border wall out of shipping containers.

NewsNation’s Ali Bradley’s live report on drug busts at the border can be viewed above.