Six people have been arrested for a November shooting rampage that killed four people and injured six at a backyard football-viewing party in Fresno, California, police said on Tuesday.The attack was carried out by members of a gang called the Mongolian Boys Society in retaliation for the murder of Randy Xiong, the brother of gang member Billy Xiong, Fresno Police Department Chief Andy Hall told a news conference. The attack shook a neighborhood that is home to mostly Latino and Southeast Asian families and prompted police to form a task force to look at the activities of Asian gangs in the central valley hub about 160 miles (260 km) southeast of San Francisco.The gunmen made their way into the yard through an unlocked gate and began firing with semi-automatic pistols shortly before 8 p.m. on Nov. 17, killing Xy Lee, Phia Vang, Kou Xiong, and Kalaxang Thao, police said.A string of tips led to Billy Xiong's arrest on Dec. 17 for mail theft and, during a search of his vehicle, police found a Glock 9mm semi-automatic handgun. A forensic analysis revealed it to be one of the weapons used in the shooting.An investigation then led to the arrests. Officials identified the other five suspects as Anthony Montes, 27, Porge Kue, 26, Johnny Xiong, 25, Pao Vang, 30, and Jhovanny Delgado, 19. Officials said they are still looking for a seventh person.Police said they are requesting they face four counts of homicide, 12 counts of attempted homicide and conspiracy to commit murder, with gang and firearm enhancements.Charges against the suspects are expected to be announced by the district attorney's office on Thursday.