Metropolitan Police units responded to a suspicious substance at the U.S. Post Office on Massachusetts Avenue Northeast several minutes after 8 a.m. Wednesday.

MPD units are working jointly with the Capitol Police to investigate. Information on the substance has not yet been determined. No evacuations have been made at this point.

“We do have an interest in it because we have Senate staff on the sixth floor” of Post Office Square, Capitol Police spokeswoman Sgt. Kimberly Schneider said. But she added that MPD was orchestrating the response.

According to MPD officer Tisha Gant, the following area was been closed off for the investigation: Northbound on North Capitol Street from E to G streets; northbound Massachusetts Avenue to E. Street; westbound from Columbus Circle to E Street; and eastbound Massachusetts Avenue from North Capitol to Columbus Circle.

By about 10:10 a.m. police determined that there was no hazardous
material on location. Emergency units have been cleared from the area.