The Joint Task Force DC, which is co-ordinating the National Guard deployments to the nation’s capital, said the attack took place at around 14:15 EST (19:15 GMT) on Wednesday near the Farragut Square Metro Station.
The soldiers had been on a high-visibility patrol near the corner of 17th and I streets – a busy lunch spot for office workers.
Metropolitan Police Assistant Chief Jeff Carroll said the suspect “came around the corner” and “immediately started firing”, adding that the soldiers had been “ambushed”.
Other National Guard members nearby heard the gunfire and intervened, holding the suspect down until police arrived, he said.
The suspect was shot four times, law enforcement sources told CBS.
One witness described to the BBC his experience of hearing gunshots, as people ran in panic and tried to take shelter in a nearby shop.
Another witness, who was in his car close to the metro station, showed the BBC footage he took of the two soldiers lying on the street in their uniforms while being treated by medics. Details on the identities of the soldiers have not yet been provided by officials.
A third person, apparently the alleged gunman, was also seen on the pavement being treated.
