A two-alarm fire that officials said may have been deliberately set gutted the offices of the American-Arab Anti-Discrimination Committee here last night and heavily damaged a popular food market in the same building on Connecticut Avenue NW.

The fire, which sent flames leaping high into the air above the four-story building and drew crowds of onlookers, came about six weeks after a bomb blast damaged an ADC office in the Los Angeles area, killing one of the group's officials.

In August a policeman was injured in the explosion of a bomb planted at ADC offices in Boston.

The ADC is a 13,000-member organization that works against what it views as discrimination against those of Arab descent in the Mideast and the United States.

No injuries were reported in last night's fire, which broke out shortly before 8 p.m. in the second-floor offices of the ADC at 1729 Connecticut Ave., just north of Dupont Circle.

Fire officials said the blaze raced quickly through other ADC offices on the third and fourth floors to the roof and sent clouds of thick smoke into Larimer's food market on the ground floor.

While the cause of the fire had not been officially determined by late last night, assistant D.C fire chief Maurice Kilby called the blaze "very suspicious."

"There's no way a fire can get that much headway so quickly," he added, referring to the rapid spread of the blaze, which burned out of control for 45 minutes and brought about 80 firefighters to the scene.

ADC deputy executive director Barbara Shahin, told a reporter she was on the fourth floor working alone and heard what she described as a "loud thud" just before the building's fire alarm went off.

Shahin said she ran out of the building as flames leaped from the windows.

"It started as a glow. Then the windows broke and then it was just spectacular," said Jann Darsie, who was dining at a restaurant across the street.

"You could feel the heat in the buildings," she said. "It was that intense."

D.C. police officer Alphonzo Liggins said he was investigating a nearby traffic accident when he saw smoke and flames spewing from the building.

"I turned the corner and saw it blazing on the second and third floor," Liggins said. "I went inside to see if anybody was there, but I didn't find anyone. By the time I got back out, the flames were coming out the windows past the sidewalk."

The ADC occupies offices at both 1729 Connecticut Ave., where the fire broke out, and in the adjoining building at 1731. The fire caused an undetermined amount of damage to ADC offices in 1731, officials said.

They said Larimer's was heavily damaged by smoke and by water poured onto the blaze by firefighters.

Fire officials estimated damage to the building and contents at about $500,000.

A consultant to the ADC, Marwan Bishara, said his organization had occupied the Connecticut Avenue offices for about four years.

Bishara, citing the previous bombing incidents, called the blaze "definitely intentional."

On Oct. 11, a bomb ripped through the ADC office in Santa Ana, Calif., killing Alex Odeh, 41, the organization's West Coast regional director and injuring eight other persons.

Investigators said the blast was apparently triggered by a device rigged to a tripwire that detonated the bomb when the office door was opened.

The night before the bombing, Odeh, considered a moderate Arab-American leader, appeared on a local television station to condemn the Oct. 7 hijacking of the Achille Lauro luxury liner by four Palestinian gunmen.

During the interview, he praised Palestine Liberation Organization leader Yasser Arafat for his role as a negotiator, calling him "a man of peace."

Following the bombing, the ADC's Los Angeles Chapter offered a $100,000 reward for information leading to the capture of those responsible for Odeh's death.

No one claimed responsibility for the bombing.