An all-out brawl with baseball bats and knives in South Boston on Sunday, which left an Asian teen dead, was sparked by the use of a racial slur, according to witnesses.

Two weeks ago, a teenage girl called several Asians visiting Veterans Park to play basketball "chinks," witnesses on both sides said.

An Asian boy in the group responded by hitting the girl, touching off a series of confrontations that ended Sunday with the death of Bang Mai, 16, of Medford. Police said he died from trauma and a stab wound.

"There is no conclusion as to whether this was racially motivated or involved gang activity, but when you have an event of this nature, obviously we're going to investigate it thoroughly," police Commissioner Kathleen O'Toole said.

The Community Disorders Unit for the Boston Police Department is investigating the incident. The unit is charged with responding to hate crimes and racial incidents. The CDU will await an investigation by the homicide unit before proceeding, police said.

One teen, Mark Brennick, 17, already has been charged for his alleged involvement in the fight Sunday, but police are continuing to search for those responsible for killing Mai.

Brennick, a resident of the nearby Old Colony housing project, was held on $10,000 cash bail in South Boston District Court yesterday after being charged with clubbing a 14-year-old Asian boy in the knee with a baseball bat.

"The evidence suggests the assault of this Asian boy from East Boston was part of a larger fight between two groups," said David Procopio, spokesman for Suffolk District Attorney Daniel Conley. "And as a result of that larger confrontation, a 16-year-old boy was killed."

Procopio said Brennick was seen "running and dropping the bat as he fled" but it was "too early to say" whether Brennick - who was arraigned on charges of assault and battery with a dangerous weapon - took part in the killing.

John Nguyen, 14, who lives in the Old Colony projects, said friction between Asian teens, most of who live in Fields Corner in Dorchester, and white teens mostly from the Mary Ellen McCormack Development, started about four weeks ago.

"Me and my friends went to the park to play basketball and they started counting how many of us were there," Nguyen said. "We were sitting on the cement stairs and they started throwing rocks at us."

Nguyen said he and seven friends left the court but were followed by the white teens and taunted. "This happened for four days straight," he said.

According to a white teen who participated in Sunday's brawl, things heated up two weeks ago after an Asian boy hit a white girl after she taunted his group with a racial epithet.

The girl rounded up several friends and confronted the Asians. A fight ensued, witnesses said.

Then, on Friday, according to witnesses, two Asian teens jumped two white teens at a beach near the park.Later that day, a fight was set up between two of the boys who fought earlier in the day.

The Asian teen won, witnesses said. "We thought that was the end of it," Nguyen said.

But a rematch was arranged for 5 p.m. Sunday.

The kids from the development called on a boy named Danny to fight for them Sunday. Danny, who stands about 6 feet 2 inches and weighs 145 pounds, was the biggest kid among both groups and he summarily beat up two Asian teens in consecutive one-on-one fights. Halfway through a third fight, another Asian ran toward the fighting at the center of the basketball court, and the melee broke out.

"I got punches thrown at me, but someone knocked down the kid and I kicked him in the head," said a 12-year-old resident of the development. "There were people with bats and knives."

Kaitlyn Shea, a resident of the development for four years, said blood poured out of Mai's nose and mouth "like a faucet."

"He seemed to be bleeding from everywhere," she said. "I was screaming for someone to help him, but everyone had run away because they heard the police coming."