Four people died Sunday night after at least two gunmen opened fire at a family party in a backyard in Fresno, California, according to police. >> Read more trending news Police continue to search for suspects in the shooting, which left six other people injured with gunshot wounds. Pao Yang, chief executive officer for the nonprofit community group The Fresno Center, said the victims included two people who were well-known in the local Hmong community. Here are the latest updates: Update 3:15 p.m. EST Nov. 18: At a news conference Monday, police Chief Andrew Hall said Sunday's shooting 'was not a random act.' 'It appears that this incident was a targeted act of violence against this residence,' Hall said. Police were investigating a possible connection between the shooting and an incident involving some people who were at the family party on Sunday night. 'We do have information that possibly some people at this party were involved in a disturbance earlier this week,' Hall said. He later added that 'everybody that (was) at this event are truly victims, however, we don't know everybody that was there.' At least two gunmen used an unlocked side gate to get into the backyard Sunday night. Hall said they appeared to have fired into the crowd in the backyard at random. 'It does not appear that they were targeting any individuals,' Hall said. 'Once they fired their rounds, they left.' He said it was pure luck that no women or children were injured in the attack, as temperatures had cooled shortly before the shooting and prompted them to go inside. About 16 men remained outside to watch a football game, Hall said. Bullets struck 10 people between the ages of 28 and 40. Hall identified the slain victims as a 23-year-old man, a 31-year-old man, a 38-year-old man and a 40-year-old man, though he declined to release their names until after all family notifications were completed. Pao Yang, chief executive officer for the nonprofit community group The Fresno Center, said the victims included two people who were well-known in the local Hmong community. He said the 40-year-old victim, 'came out almost every month to sing to our mental health clients.' Officials are offering a $5,000 cash reward for anyone with information leading to the arrest of the people responsible for Sunday's shooting. Update 2:20 p.m. EST Nov. 18: Authorities in Fresno are holding a news conference to update the public on Sunday night's deadly shooting. Update 3:23 a.m. EST Nov. 18: According to the Fresno Bee, the shooting occurred shortly before 8 p.m. outside a home on East Lamona Avenue. 'Everyone was watching football this evening when unknown suspects approached the residence, snuck into the backyard and opened fire,' Fresno police Lt. Bill Dooley said late Sunday. The slain victims were all men in their mid-20s to mid-30s, the Bee reported. Five others who were shot are being treated at Community Regional Medical Center, while a sixth victim who suffered 'a graze wound' was taken to a different hospital, CNN reported. Police have not released any information about possible suspects or a getaway vehicle, the outlets reported. Original report: A family gathering was disrupted by gunfire when a shooter opened fire, striking at least nine people during a backyard football watch party in California, police say. An unknown suspect snuck into the backyard and started firing indiscriminately while multiple people were watching a football game around 7 p.m., KMPH reported. Several people were taken to the hospital. This is a developing story. Check back for updates.