FRESNO, Calif. – Police are investigating whether there’s a connection between an increase in local gang activity and the shooting Sunday night that left four people dead and six wounded at a backyard football-watching party.

Law enforcement officials are attempting to prevent retaliation after an attack by at least two unidentified assailants in a residence populated by members of the Southeast Asian Hmong community, who have a large representation in the part of Fresno where the shooting occurred.