Leesburg police investigators responded to the apartment complex on Edwards Ferry Road, Northeast around 12:15 p.m.
When they arrived, the victim told them that the man repeatedly made unwanted advances toward her and tried to kiss her.
When she tried to leave, he kept blocking her from exiting until she forced her way past him.
Police charged 41-year-old Teferi Aynalem of Beltsville with one count of abduction and one count of assault.
Aynalem was jailed in Loudoun County without bond.