Nguyen Thanh Hoang, a 59-year-old Vietnamese refugee, was sitting with his daughter in the basement of their small brick home in Arlington when three explosions shook the house in rapid succession.

Stunned, Hoang scooped his seven-year-old child in his arms, dashed upstairs and leaped through a small casement window to safety.

His home was engulfed in flames, gutted by a late night firebombing last week that some Vietnamese said yesterday may reflect rising tension in Washington's burgeoning Indochinese community.

Hoang, a former Saigon journalist and publisher of Vietnamese publications here, was said to be in seclusion with his daughter yesterday, fearful that whoever bombed his home Thursday may still be after him.

Arlington homicide detective Clyde Hall said yesterday that Hoang told him he had received verbal threats after he had began researching an article on a pro-Communist Vietnamese group that had supposedly begun operating recently in Washington and Los Angeles.

Hoang, described as staunchly anti-Communist, had come to Arlington in 1975 shortly before the fall of South Vietnam, a former Vietnamese legislator said.

"He was very well known in Saigon," the former legislator said. "When he came here, he began publishing 'Tien Phong,' a Vietnamese publication for Arlington refugees who could not speak English."

Hoang's publications, which he prepared in his home, often reflected what his friends described yesterday as his strong anti-Communist views.

Nguyen Bich, a Vietnamese specialist with the Arlington schools, said that Houng "is very controversial. He also writes [critically] about many things, like Catholicism . . . I think it would have been very unusual for a Vietnamese person to do this."

Deputy Arlington Fire Marshal Buck Swartz said "three separate and distinct fires" were set on the front porch, at the rear door and on Hoang's late model station wagon at 15 N. Highland St. in the Ashton Heights neighborhood near Fort Myer. All were set "with a flammable liquid, possibly gasoline," he said.

Other fire officials put damage to Hoang's home at $125,000, with another $10,000 damage to his car and garage.

Neighbors some three blocks distance from Hoang's home said the explosions were loud enough to scare them from their sleep.

"It was just awful," said a woman who lives next door to Hoang. "My brothers are firefighters so I know about fires, but this was so close. I didn't sleep at all that night."

"It sure looks like someone was out to get him," said one firefighter who was at the scene for several hours after the blaze.

Another Vietnamese neighbor of Hoang's was more philosophical as he looked at the charred house yesterday. "The war is not over," he said, "it is never over."