An off-duty D.C. police officer caught three persons as they jumped from a second-story apartment, and a total of 14 persons, including three children, were treated for injuries after a domestic argument resulted in some type of acid being sprayed around an Anacostia apartment, according to a D.C. police spokeswoman.

The officer, identified as Chaulis Jones Jr., a 16-year member of the force, caught the three as they jumped from a second-story window of an apartment building at 1849 Good Hope Rd. SE, police said.

Three adults and three children were taken from that address to Greater Southeast Community Hospital, where they were treated for chemical burns and for troubled breathing.

Police said a domestic argument apparently ended with someone splashing five gallons of an unknown chemical on the occupants of the apartment.

A seventh resident of the building and seven firefighters were also taken to the same hospital and were treated for difficulty in breathing, police said.

Hospital officials said three of the victims were admitted: a man who suffered respiratory spasms and burns to his left arm; a woman who suffered burns to the leg, and a man who suffered cornea and arm burns. Their conditions were not available late last night and it was not known if any of the injured firefighters were among those admitted.

In an unrelated incident, a second off-duty D.C. police officer, who was working in uniform as a guard at a downtown bank, foiled an armed robbery attempt yesterday when he was able to disarm the would-be robber, D.C. police said.

Officer Wayne L. Nicholson, working as a guard at the National Bank of Washington at 301 Seventh St. NW, saw a man with a gun enter the bank about noon and heard him announce, "This is a holdup," police said. As Nicholson struggled with the man, the gun discharged once, striking a wall, police said.

Police have charged James R. Shepherd, 35, of no fixed address, with attempted armed bank robbery, a police spokeswoman said.