Six others were wounded after assailants opened fire at a backyard gathering on Sunday evening in the California city

This article is more than 10 months old

This article is more than 10 months old

Police in the California city of Fresno are searching for two assailants who sneaked into a backyard party on Sunday evening and opened fire on a small crowd that had gathered to watch football on television. Four people were killed and six wounded.

The house where a Hmong ethnic minority group of family and friends got together was deliberately targeted but the shooters fired at random once they saw men in the yard, police said.

“They fired randomly into the crowd. It does not appear that they were targeting any individuals, and once they fired, they fled,” said Andrew Hall, Fresno’s police chief, on Monday.

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Hall said there was no immediate word on a motive, and so far there was no indication that any of the victims knew their attackers, though most could not see them. They described seeing only flashes when the semiautomatic pistols were fired. Officers went door to door looking for surveillance video that might help them track down suspects.

The party “was just a family event”, Hall said. The chief said the shooting scene was graphic and that officers are making the case a priority.

“We’ve got a single focus within the organisation, and this is not going to be tolerated in the south-east [Asian] community or any other community in Fresno,” he added.

California has the nation’s highest population of Hmong, a south-east Asian ethnic minority, and Fresno has the second-highest population in the United States.

The Fresno County coroner’s office identified the dead as Fresno residents Xy Lee, 23; Phia Vang, 31; Kou Xiong, 38; and Kalaxang Thao.

Three were found dead when emergency crews arrived. A fourth person died at a hospital. Three remained in hospital on Monday in a serious condition, Community Regional Medical Center said in a statement.

Pao Yang, CEO of the Fresno Center, a Hmong community group, said two of the victims were well-known Hmong performers, including a man who regularly sang for mental health clients. He said community elders have offered help to the center.

“Our community is in mourning, and we still don’t know what’s going on or who are the suspects,” he said.

Hall said police were investigating whether the shooting was connected to a recent disturbance involving some of the people at the party. He also announced the establishment of an Asian gang task force before the Hmong new year out of concern about the possibility of more violence or retaliation.

Facebook Twitter Pinterest Police and emergency personnel at the scene of the shooting in Fresno on Sunday. Photograph: Larry Valenzuela/Associated Press

Some residents complained of other shootings in the neighbourhood recently. The home where the attack took place is near an industrial area with commercial buildings close to Fresno airport.

Calvin Gatison, who lives on the same block, said the street had been peaceful for years, but at least two shootings had happened in recent weeks.

It was at least the second fatal gun attack on Sunday in south-east Fresno, the Fresno Bee newspaper reported. A man in his 20s was shot dead early on Sunday at a home in another part of the city.