Updated post at 7:58 a.m.
D.C. police said no hazardous material was found in the package and the woman is being taking for a psychiatric evaluation.
They did not specify what the package was.
Original post at 7:50 a.m.
D.C. police closed the 1100 block of Constitution Avenue NW for a suspicious package.
A woman told authorities she had a bomb, police said. The woman is in police custody, and investigators are working to clear the package.
A D.C. police traffic alert said 10th Street NW and Pennsylvania Avenue NW are also closed.