Warning to prison guards and officers on street about possible attacks from "Black Guerilla Family" at 6. #ABC7now pic.twitter.com/rbllEszhA5 — Dan Noyes (@dannoyes) August 4, 2016

SAN FRANCISCO -- An urgent bulletin is going out to law enforcement Wednesday, warning of a new threat of attacks against officers on the street and in prisons.It has to do with what's called Black August.A reporter for KGO-TV - KABC's sister station in San Francisco - obtained the bulletin from a law enforcement source.The bulletin from the Federal Bureau of Prisons, Sacramento Intelligence Unit and the FBI's National Gang Intelligence Center warns of increased risk for violence against prison guards and police officers during Black August.The prison gang Black Guerilla Family started Black August in the 1970s to honor fallen members.One of the most prominent, Hugo Pinell, served 46 years in solitary confinement after a San Francisco rape conviction, and after killing a prison guard and slashing the throats of two other guards who survived during an escape attempt in 1971.Former San Quentin inmate Jerry Elster remembers Pinell as a freedom fighter. "When I went to prison at 20 years old, there was somebody there to remind me not to compromise my integrity," said Elster, who currently works as the healing justice coordinator for American Friends Service Committee (AFSC) , a Quaker organization devoted to service, development and peace programs throughout the world.Last summer, just 12 days after corrections finally released Pinell from solitary, he was stabbed to death in a riot at State Prison Sacramento.The bulletin says the Black Guerilla Family believes state prisons worked with the Aryan Brotherhood to kill Pinell.At the very least, Elster believes the state had a duty to protect Pinell. "I mean, it's only those who are charged with authority and protection, of protecting and housing of Hugo Pinell who have to bear that responsibility," Elster said.The bulletin warns an inmate source: "Claims the BGF has a 2-for-1 kill policy." That the BGF is "going to kill correctional officers and Aryan Brotherhood gang members to send a firm message. And the attacks will occur across the country, not just in California, and will likely occur during the BGF's memorial celebration of Black August."The Bureau of Prisons and the FBI declined to comment for this report.Retired FBI special agent Rick Smith said: "I think it's serious. They put that bulletin out, they don't want to be caught with something happening with the information they have and not disseminating it."Also included in the bulletin is the FBI's Baltimore office report: "BGF members reportedly discussed how they could ambush law enforcement officers who were parked in alleys or side streets."It also mentions the San Francisco Bay View newspaper for publishing articles, "suggesting California Department of Corrections and Rehabilitation responsibility for Pinell's murder, and promoting Black August celebrations as a platform for action."Bay View editor Mary Ratcliff is surprised her newspaper is named in the bulletin, but is worried about the message. "This statement from the Department of Justice puts black people in danger," Ratcliff said. "Because it is promoting the idea that there is a war going on between black people and law enforcement."The bulletin also includes a drawing from the newspaper by a BGF member, showing the logo and a gorilla eating a pig.Ratcliff downplays the reference to violence against police officers. "A depiction like that is a release, it's yeah, go for it, that's how I feel. Now, I don't have to do it," she said.Smith from the FBI said the bulletin does not come as news to officers, in prison or on the streets. They know how dangerous their jobs have become. This is yet another heads up.