Two robbers who attempted to hold up the Dancing Crab restaurant on upper Wisconsin Avenue were believed trapped inside the building early this morning by D.C. police who arrived before they could flee, according to police and witnesses.

Several shots were reportedly fired, and one of the restaurant employes was believed taken hostage, according to initial accounts, but details remained sketchy early this morning.

Another employe who escaped from the restaurant at 4611 Wisconsin Ave. NW was taken to Sibley Hospital for treatment of an injury, police said.

According to police, four employes were in the restaurant just before midnight when two men, one armed with a shotgun, entered and ordered the safe opened. The employes said they could not open the safe, and the robbers ordered some of them into a back room.

Police said three of the employes escaped, but a fourth, a woman, was not accounted for early this morning.

One witness said police were called after a woman who was talking by telephone to an employe inside the restaurant heard the man shout:"No, no, no!" and then heard the telephone drop.

Officers arrived swiftly, cordoned off several blocks around the area, and surrounded the restaurant. A police helicopter from Maryland hovered overhead. Police said the D.C. police helicopter was not operating yesterday.