Syrian state television warned citizens on Thursday that gunmen were planning to attack people in the capital using military uniforms as disguises.
Several neighbourhoods in Damascus have been rocked over the past five days by fierce clashes between security forces and rebels fighting to topple President Bashar al-Assad.
Syria TV said uniformed men in those districts may not actually be from the armed forces.
"Armed men in Tadamon, Midan, Qaa and Nahr Aisha (neighbourhoods) are wearing military uniforms with the insignia of the Republican Guard. This confirms they are planning to commit crimes and attack people, exploiting the trust of citizens in our courageous armed forces," Syria's official channel said in a message flashed across the screen.
Opposition activists have accused security forces of using heavy artillery to attack rebellious areas like Tadamon and Midan, forcing residents to flee.
They have also said pro-Assad militiamen, called "shabbiha" in Syrian slang, have raided opposition areas in the capital.