A man was sexually assaulted early Friday near the National Gallery of Art, according to D.C. police.

The victim told police he was walking home about 3 a.m. when the incident occurred. Near the intersection of Sixth Street and Constitution Avenue NW, a man approached the victim and brandished a knife. The man then sexually assaulted and robbed the victim. The man then fled on foot.

Police describe the suspect as a black male in his 20s who is about 5-feet 8 inches tall with a slight build. The suspect had dreadlocks and was wearing red shorts at the time of the assault. The suspect spoke with a soft voice, police said.

Friday morning, police said a man had been robbed and sexually assaulted by someone bearing a similar description in the 1200 block of 18th Street NW. They later said there was only once incident, the one at Sixth Street and Constitution Avenue NW.

Anyone with information on the case should call D.C. police at 202-727-9099 or make an anonymous tip by text messaging the department’s tip line at 50411.

This item has been updated.