Rockville Police are working a potential domestic dispute situation on Azalea Drive.
It is unclear whether the man may be inside or not.
Authorities are trying to make contact with him, police say.
The barricade started just after 6 a.m. inside a home in the 600 block of Azalea Drive in Rockville, Montgomery County Police officials say. Police believe it's a domestic dispute between a woman and an allegedly armed man. She left when she felt threatened.
Police have yet to make contact or communicate with the man. There is no word as to what exactly led to the incident.
This is a developing story. Check back for updates.