Story highlights There could be as many as 12,000 inmates skipping meals, advocacy group says

Inmates are upset about solitary confinement policy

Prison officials say leaders of the strike will face solitary confinement

Thousands of California state prisoners, angry about what they call harsh treatment, have been on a hunger strike that enters its ninth day Tuesday.

There could be as many as 12,000 inmates skipping meals in at least eight California prisons, a prison advocacy group said. Many inmates are angry about a practice of keeping them in solitary confinement for too long, the group said.

"We are hoping that this widespread participation will push (prison officials) to negotiate and honor the basic demands of the people locked behind those walls," said Isaac Ontiveros, a spokesman for Prisoner Hunger Strike Solidarity. "You have people in there that have been in solitary confinement for 20 years. They just want to change their conditions."

The California Department of Corrections and Rehabilitation released a statement last week saying it is "responding to a hunger strike disturbance by thousands of inmates in several correctional facilities."

Prison officials said it would punish inmates who were not eating and leaders of the strike will be removed "from the general population and be placed in an Administrative Segregation Unit."

The prisoners have made five demands which include a change in the prison policy that makes inmates go through an interrogation process where they have to incriminate themselves and identify other inmates who are involved in breaking rules in order to get out of solitary confinement. They are demanding an end to group lockdowns and want more privileges for those in solitary confinement, such as winter clothes and nutritious meals.

Prison officials have said that placing prisoners in segregation units, or solitary confinement, makes the facilities more safe and helps guards deal with gang violence.

The strike started on September 26 and is the second strike by prisoners this year. One in July lasted for weeks.

"Right now we are seeing nothing but crackdowns from the CDCR," said Ontiveros. "We are hoping that there will be some fruitful negotiations, but ironically they have threatened prisoners with more isolation."

Demonstrators have called a rally Wednesday outside the corrections department headquarters in Sacramento to express solidarity with the hunger strikers.