A pool-side party at a Herndon recreation center exploded into a fierce brawl on a weekend night in June when a Vietnamese man told another to leave. According to court testimony, at least six men brandished machetes and knives in a crowd of 30 people and one man suffered several deep gashes after he was slashed with a machete.

"When the police got there, someone came out and said everyone was fine, that it was just a fist fight," said Investigator Brad C. Anzengruber of the Herndon Police Department. "Fortunately, the police officer decided to stay and look around and found blood all over the place." Police also found six machetes and knives stashed under the steps and bushes outside the clubhouse.

Four weeks later on a sweltering Saturday afternoon, two groups of young Vietnamese men gathered in a department store parking lot in the heart of Arlington's Little Saigon, the largest Vietnamese business district in the Washington area.

County police say arguments and threats erupted into a show of force: knives, meat cleavers, baseball bats and nunchaku, two lengths of wood held together by a chain and swung at an opponent. A gunshot was fired, one man was stabbed, several others wounded, two nearby cars were damaged heavily, police said.

Thirteen police units responded to the scene, and 10 men allegedly involved in the fight were arrested.

After the parking lot brawl, Arlington County police issued a press release declaring, "Police haven't learned the reason for the fighting, but it may have to do with gambling and extortion."

A week later, county police offered a different theory, saying: "At the root of the incidents is a long-standing feud between rival Vietnamese gangs."

The Vietnamese community, already angered that the usual tranquility of its neighborhoods had been shaken, also was upset with that official explanation for the trouble.

"There are no gangs in this area," said Kim Cook, of the Mutual Assistance Association, a consortium of refugee assistance programs. "The incidents have been overblown. The police should come talk to us instead of sitting there speculating. You've got to distinguish between what is real and what is gossip."

The Vietnamese community blames the violent outbursts--there have been six reported in June and July--on frustrated young refugees struggling to cope in an alien and sometimes hostile environment, young adults who are too old for the American educational system and unable to obtain jobs and people who have fallen through the cracks of the established refugee-aid programs.

Police, who describe the Vietnamese as uncooperative and "clannish," say they are unable to pinpoint the causes of the trouble.

"There is this undercurrent and rumor that says these things are going on," said Fairfax County Commonwealth's Attorney Robert F. Horan Jr., referring to allegations of gang wars and so-called "protectionist rackets" in which shop owners are targets of extortion in exchange for protection from gangs.

"But you can't be certain of the problems because of the Vietnamese community's unwillingness to report it. You'd feel a lot more confident if you had the ties and sources that you have in the average community," Horan said.

Both sides concede they have made little effort to learn about each other, but the violence appears to have brought to the forefront the need for communication.

Arlington police acknowledged they did not talk with representatives of the Vietnamese community before issuing statements about the causes of the fights. "They say there are no gangs," police spokesman Tom Bell said recently. "I guess we believe them."

Local Vietnamese residents also admit they have been reluctant to assist police in criminal matters. "We just came from a police state," Kim Cook said. "There you don't tell the police anything or you can lose your life. That is what the people brought with them."

"A lot of incidents are not reported to us," said Al Santiago, a Spanish-speaking Fairfax County crime prevention officer who centers his job on settling conflicts in local ethnic communities. "Some of these groups take care of their own problems."

An estimated 18,000 to 20,000 Vietnamese refugees live in the Washington area. The largest concentration of refugees has settled in Arlington where public transportation is readily available and housing--much of it older, run-down apartment complexes--is more affordable, according to Kim Le, a Vietnamese social worker for the Arlington County Social Services Division.

Large numbers of Indochinese refugees also have moved into the Bailey's Crossroads and Seven Corners areas of Fairfax County and Falls Church.

The centerpiece of the Vietnamese community--and the scene of most of the recent street fights--is Little Saigon, a three-block stretch of Vietnamese-run restaurants, clothing shops and department stores in Clarendon in central Arlington.

On Saturday mornings, the narrow aisles of its grocery stores are jammed with Vietnamese women picking over the locally grown fruits, vegetables and herbs native to their homeland. On Saturday evenings, the sidewalks are dotted with clusters of young adults seeking companionship in a familiar language, a native dinner or a pool game.

It also is where the restless, uneducated, unemployed young Vietnamese men frequently gather, seeking solace from acquaintances in similar situations, according to Kim Cook and others who have followed the paths of the youths unable to find a place in their new American communities.

"They come here because it is the only gathering place in the area for Vietnamese," said one Vietnamese businessman in the area. "They're not going to go to Tysons Corner--they'd really stick out. But here, they blend in. Here are their restaurants, their own people."

"Some of these young men have very low self-esteem when they come here," Santiago said. "They turn to groups already formed. You may see them all grouped together on a corner. They might be just talking, enjoying fellowship. Sometimes they may be perceived as a gang gathering together, as a threat to us in the wrong way."

"Many of them are very frustrated, very depressed," said Mai Duc, a counselor for a Falls Church-based refugee program. "They have no money, no jobs, and sometimes they turn to crime."

According to youths involved in some of the street fights, and others who say they are acquainted with those involved, the disputes arose either out of petty jealousies or occurred after a few rounds of drinks.

These youths and police have said one fight reportedly involved a dispute over a girl; another fight ensued after one group of youths slashed the tires of another youth. The Herndon fight apparently was sparked by a "question of honor," one man defending his right to remain at the party in the face of another man's demands, according to testimony in Fairfax County Circuit Court.

"These people aren't really a gang," said Thanh Vu, 24, of Arlington who said he is acquainted with several of the young men arrested in the brawls. "It is a situation that happens when someone tries to cause a problem with someone else, and another friend tries to protect that friend and so on."

Members of the Vietnamese community say the youths who are alleged to have participated in the violence are representative of a larger social problem, deeper than the sporadic criminal incidents.

Bich Nguyen, 21, of Arlington was charged with malicious wounding for allegedly using a machete to attack another Vietnamese man during the June 11 fracas at the Hunters Creek pool clubhouse in Herndon.

In an interview, Nguyen, speaking in broken English, said he was acting in self-defense when another Vietnamese man raised a chair toward him. The man with the chair testified at a preliminary hearing that he was holding up the chair to protect himself against Nguyen and others.

Nguyen said that when he arrived in the United States three years ago from a Vietnamese refugee camp, he was too old to enter the American school system, knew no English and was unable to find a job. According to Nguyen, he now is taking English classes in an adult education program and is working a few hours a week as a printer.

He said he also is trying to raise his four younger brothers, ranging in age from 11 to 18, in a worn high-rise apartment complex in Arlington. The five brothers pay the rent and grocery bills with the welfare money paid to the youngest brothers and with the wages Nguyen and an 18-year-old brother make between holding part-time jobs.

"It's a very grim picture," social worker Kim Le said about the situation facing many of the young Vietnamese that he works with.

Although every refugee who enters the United States, is expected under law to be sponsored by a friend or relative, "the help they get is pretty lose," Le said.

Vietnamese refugees are eligible to receive U.S. government welfare assistance--$214 a month--for 18 months. "After 18 months, they are totally cut off except for food stamps," Le said.

Kim Cook and others say police have not attempted to understand the deeper social implications behind the street fights.

Local police departments employ no Vietnamese-speaking officers and offer no formal training to officers in dealing with the pecularities of the Vietnamese community despite its rapid growth over the past five years.

Arlington Police Officer E.M. Robinson, whose daily patrol beat includes the heaviest concentration of Vietnamese businesses in the Washington area, said he has some regret that he has little contact with the businessmen in the area and has no personal contacts in their community.

"I seldom have trouble here, so I tend to look elsewhere," Robinson said.

The recent incidents of violence have spawned several committees and tasks forces composed of members of the Vietnamese community, representatives of refugee aid programs and police and government officials, all aimed at improving relations among the different factions.

"The sudden influx of Vietnamese is forcing people to see things a little different," Fairfax Police Officer Santiago said. "It is new to the police, the school systems, the neighborhood. Sometimes we over react because we don't understand. I hope that is changing now."

Members of the Vietnamese community note they also will be responsible for initiating any changes.

Said Mai Duc: "The refugees have lost everything in their own country and have come here to try and build up a new life. Maybe they have some difficulties, but they are going to have to help solve them."