The hunger strike, which began Monday, involves as many as 6,000 prisoners who say conditions in isolation cells need to be improved. They claim unfair gang-security measures at the state prisons, the San Francisco Chronicle reported Thursday.
The prisoners first went on strike in July, at which time they received "some privileges such as sweat pants (and) colored pencils," a statement by the Prison Hunger Strike Solidarity Coalition read Tuesday.
Terry Thornton, spokeswoman for the California Department of Corrections and Rehabilitation said policies on isolation units and gang security are being reviewed but the process could take months.
She said prisoners have been told they will be disciplined if they join the strike because they will be "participating in a mass disturbance."
Avril Lavigne denies racism in 'Hello Kitty' music video
Jeb Bush 'thinking about running for president' in 2016