2 Killed as Gangs Turn Party Into Battleground : Violence: Girl, 16, and man, 26, die. Six people also are wounded at large birthday celebration in Paramount.

A teen-ager’s birthday party in Paramount turned into a bloody melee early Sunday when feuding gang members started declaring their allegiances and then opened fire on one another, killing two and wounding six among a crowd estimated at 200, authorities and witnesses said.

The door of a Ford Mustang, a large splotch of dried blood, smashed beer cans and bullet-riddled cars dotted the hot pavement in the 15300 block of Castana Street on Sunday as remnants of the Los Angeles area’s most recent weekend of gang bloodshed.

Elsewhere, a 59-year-old pedestrian in downtown Los Angeles and an 11-year-old bystander near Torrance were among at least four others who died over the weekend as the result of suspected gang activities, even as authorities arrested 326 people in raids targeting gang members.

At the Paramount party, “there must have been five gangs here and the guys, they just don’t get along,” said Raul Medina, whose 15-year-old sister--herself a gang member--was throwing herself a birthday celebration. “The guys started throwing their gangs out and then came the guns--30, 40 of them.

“Then the shooting and all the screaming started,’ said Medina, who was released by sheriff’s investigators after questioning. “It was like the . . . Fourth of July.”

As neighbors cleaned up the mess Sunday, Jaime Olmos stood beside his wrecked car and tried to figure out why gang members had decided to smash it with a brick. A few houses down, 49-year-old machinist Aurelio Cruz questioned why deputies didn’t break up the party hours earlier, when they responded to complaints about noise and yelling.

And across the street, gang members wondered if the incident would spoil plans for their next party.

“Naaah,” said one young man, who identified himself only as Pancho Villa. “Next party next Saturday!”

Investigators had several people in custody Sunday, but did not release the names of any possible suspects or the victims in the case.

Killed by gunfire were a 16-year-old girl and a 26-year-old man. One man was hospitalized in very critical condition on life-support systems, another in critical condition, another in serious condition and two in stable condition. A sixth victim was treated and released, police said.

The violence appeared to mirror a pair of disturbing trends detected this year by Los Angeles-area authorities: a 135% jump in Latino-on-Latino gang murders, up to 47 through August; and a 69% increase in gang killings within unincorporated areas of the county that are patrolled by the Sheriff’s Department, up to 103.

Participants said almost all the gang members in the Paramount brawl were from among five or more local rival Latino factions.

The trouble started about 2 a.m., witnesses said, when some youths began flashing gang signs and calling out their affiliations, as if to challenge rivals.

Several gang members jumped a rival as his buddies fled, hitting him repeatedly over the head with a beer keg and leaving him “a vegetable,” in the words of one witness. Fistfights spilled into the street and soon shots were fired.

“I was sleeping and my brother came into my room and said, ‘They’re shooting!’ said one 15-year-old neighborhood boy, who did not give his name for fear of gang retaliation. “Everybody was screaming. I didn’t want to look outside the window because the bullets might come in.”

A gang member said: “These people have really good guns. If they’re going to shoot somebody, they want to kill ‘em.”

Deputies arriving on the scene stopped a speeding car and found a shotgun inside. Six passengers--four women and two men--were detained as possible suspects.

Another shotgun and four other guns were also confiscated separately.

In other local weekend violence:

* Yun Choi, 20, of Norwalk was shot and killed early Sunday after arguing with a group of at least six men on 219th Street in Hawaiian Gardens.

* An unidentified man was shot and killed early Sunday after an argument with another man downtown. Police were seeking a suspected gang member.

* Shirley Arnel, 59, died Saturday of injuries sustained earlier in the week when she was standing on a downtown corner and was struck by a stray bullet believed fired by a gang member. A teen-age boy was arrested.

* Jose Gonzales, 11, was shot and killed Friday evening as he stood talking with friends in the driveway of his home near Torrance. The bullet, fired from a passing car, was apparently meant for a gang member also standing on the street, police said.

Under Operation Hammer, the city’s anti-gang offensive, Los Angeles police over the weekend targeted Westside and San Fernando Valley streets and made 326 arrests, nearly half of them believed to be gang members. Charges ranged from misdemeanor traffic violations to assault, drugs and robbery, police said.