Two persons were killed last night and two others injured in a fire that broke out in a Northeast Washington row house described by a fire official as uninhabitable as a result of a previous blaze there earlier this month.

None of those killed or injured in the fire, which was reported shortly before 9 p.m. at 1365 G St. NE, could be identified immediately.

Last night's fatal fire came only five days after two persons were killed and 10 injured in a blaze in an abandoned row house on Eighth Street NW.

That fire was blamed on the misuse of a kerosene heater. Fire officials speculated that last night's fire may have been caused by the use of a propane heater in the G Street house.

After the earlier fire at the G Street house, both electricity and natural gas service reportedly were cut off. The second floor of the house was said to have been boarded up.

"There shouldn't have been anybody in there," Battalion Fire Chief Louis Carpenter said last night of the two-story brick row house on G Street.

"It was uninhabitable," he said.

However, neighbors said they knew of several persons who stayed in the house despite the lack of utilities.

After entering the house last night firefighters said they found on the first floor a propane gas tank of the kind often used to supply fuel for cooking in recreational vehicles.

Firefighters arriving at the G Street NE address last night encountered flames on both the first and second floors, officials said.

The two injured persons were reportedly helped by neighbors to flee from the burning house.

The two persons who were killed--a man and a woman--were found in a front bedroom on the second floor, firefighters said.

They said the intensity of the flames prevented firemen from reaching the bedroom for five minutes after their arrival.

One neighbor who said he smelled smoke and saw the flames said he had tried to enter the house.

"I went in the front door," said Reuben Ward, "but the flames were just too hot, and there was no way possible to go further."

Officials said they could not determine immediately how much of the damage to the house was caused by last night's fire and how much resulted from the previous blaze.