D.C. police arrested a 22-year-old man last night and charged him in connection with the Tuesday night firebombing of a Northeast Washington home that seriously injured six children, police officials reported.

Police said Curtis Kelvin Pixley Sr. of 2923 South Dakota Ave. NE was arrested at his home about 8:20 p.m. on a D.C. Superior Court warrant charging him with arson.

Pixley, who lives about three blocks from the scene of the fire at 2815 Myrtle Ave. NE, was being held last night in the central cellblock at police headquarters pending arraignment.

Investigators declined to specify what evidence led to the arrest, but earlier yesterday, Lt. Carl Alexander, who heads the police department's burglary and arson squad, said the firebombing was apparently related to a fight involving a large number of teen-agers at a nearby school playground about two hours before the 9 p.m. blaze. Alexander said more arrests are possible in the incident.

Two children injured in the blaze were still in critical condition last night at Children's Hospital, and five other persons, including one adult, remained hospitalized. Thirteen other persons were left homeless by the fire and Red Cross officials said yesterday that they were being housed temporarily at a hotel.

In an interview yesterday afternoon, a 13-year-old female resident of the Myrtle Avenue house told a reporter that an after-school shoving match between her and a classmate may have triggered the playground fight at Woodridge Elementary School and the subsequent firebombing.

"I was just coming out of school when this girl pushed me," she said. "I pushed her back."

The girl said more young people joined in the fracas. She said the melee continued after she left the schoolyard and returned with several of her brothers and sisters.

D.C. police were called to the disturbance, but officials said the crowd dispersed at about 6:45 p.m. when scout cars arrived with sirens blaring.

Jean Moore, 23, an occupant of the house and the mother of three of the injured children, said there was no warning before the firebomb was tossed into the living room of the tiny frame house where about 20 persons, most of them related, were staying.

"All of a sudden something came through the window and exploded," she said. "We said, 'Get the children,' and everybody ran."

As the flames filled the living-room of the house, residents smashed windows and threw several children to safety before jumping out the windows themselves.

Firefighters from Engine Co. 17, located about a dozen blocks away, arrived within minutes, officials said.

As other firefighters arrived, residents told them that several children were trapped in the blazing house.

Four firefighters beat back flames coming out the front door and windows of the house and rushed in looking for children in the smoke-filled back bedroom.

Four children were located in the room, and "we started giving them mouth-to-mouth resuscitation as we carried them," said Firefighter Thomas Taylor.

Moore's 7-month-old son Frederick remained in critical condition at Children's Hospital last night, while two others, Rontae, 3, and Kearston, 5, were listed in serious condition.

The fire, which investigators said they believe was touched off by a container filled with flammable liquid--a molotov cocktail--gutted the living room of the four-room, single-story home, officials said.

Yesterday, residents picked through some of the belongings that had been salvaged from the house--baby toys, clothes, household items.

"All those little children in the house..." said Beatrice Martin, one of the occupants. "Nobody in their right mind could have done this."