District of Columbia police say they've made the largest seizure of synthetic drugs in the city's history — more than 260 pounds. That's a street value of roughly $2.3 million.

Police and prosecutors say the drugs were shipped to the nation's capital from the West Coast. Two men face federal charges of possession with intent to distribute. Each faces a maximum penalty of 20 years in prison.

A police task force found the drugs at a shipping company in Maryland. Police say undercover officers delivered them on Tuesday to a storage facility in northwest Washington, where they were met by 41-year-old Yenework Abera of Alexandria, Virginia, and 33-year-old Siraj Issa of Washington.

The men have been detained pending a hearing on Sept. 8. Issa's attorney says he will plead innocent. Abera's lawyer did not immediately return a message.