WILKES-BARRE, Pa. (WHTM) — Federal authorities say they are investigating after several ballots were mishandled and thrown out by Luzerne County election staff.

Authorities say nine Pennsylvania military ballots were thrown away, seven of which were for President Donald Trump. In addition to those ballots, officials found four empty absentee ballots whose contents were found at an outside dumpster.

U.S. Attorney David Freed said federal authorities were alerted Monday to the discovery by the Luzerne County district attorney, prompting the inquiry by the FBI and state police.

“At this point we can confirm that a small number of military ballots were discarded,” Freed’s office said in a statement.

“Two of the discarded ballots had been resealed inside their appropriate envelopes by Luzerne elections staff prior to recovery by the FBI and the contents of those 2 ballots are unknown.”

Since Monday, the FBI says it has conducted several interviews and have gathered and reviewed certain physical evidence. They say election officials in Luzerne County have been cooperating with the investigation.

Federal authorities say they are continuing to investigate.