Two men suspected of trafficking narcotics through Oklahoma are in custody.
Their arrests stem from an opium investigation.
Thirteen-and-a half pounds of the drug was mailed to a small post office in Delaware County.
Investigators say the package started out in Laos; some red flags went up once the box made it to customs in Dallas.
Federal agents were notified and a sting operation was set-up at the post office in Colcord.
That's where investigators say 32-year-old Xue Yang and 25-year-old Wang Chong Khang picked-up the delivery.
The two were arrested moments later.
Immigration agents are also investigating the case.
The two men are scheduled to be back in a Delaware County courtroom on Monday.
