(CNN) The Nebraska State Patrol seized nearly 120 pounds of the drug fentanyl -- enough to kill about 26 million people, according to estimates by the US Drug Enforcement Administration.

On Thursday, Nebraska Gov. Pete Ricketts announced the bust, considered the largest in the state's history and one of the largest in the United States.

Authorities seized 118 pounds of fentanyl during a routine traffic stop April 26 on Interstate 80 near Kearney. Troopers became suspicious of a semi-truck driving on the shoulder lane, searched the vehicle and found drugs in a hidden compartment, according to Nebraska State Patrol Col. John Bolduc.

Breaking: The 118 pounds of opiates seized by troopers in April has been confirmed as the NSP Crime Lab as entirely fentanyl.



The largest seizure of fentanyl in Nebraska history and one of the largest ever in the US. pic.twitter.com/kHrv3lnyGH — NEStatePatrol (@NEStatePatrol) May 24, 2018

At first, troopers believed they had found mostly cocaine, but further testing showed it was all fentanyl.

Troopers did not immediately test the drugs due to the "dangerous nature of the substance," the Nebraska State Patrol said.

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