Thousands of California prisoners have refused meals since the beginning of July in protest of conditions and treatment in that state’s prison system. Many have not eaten since July 1 and are suffering from dramatic weight loss and starvation, according to the Los Angeles Times.

Estimates of inmates involved in the widespread hunger strike vary. At the peak of the strike earlier this month, the California Department of Corrections and Rehabilitation told a prison advocate blog that at least 6,600 inmates had refused to eat. The Los Angeles Times reported that inmates at one-third of the state’s prisons are participating.

State corrections officials said July 21 that the hunger strike is over. “Most inmates at Pelican Bay started eating again last night, and as of 1 p.m. today they were all eating,” said Terry Thornton, spokeswoman for the California Department of Corrections and Rehabilitation.

But prisoner advocacy groups and defense attorneys told the Huffington Post that 1,500 are still refusing food at three prisons: Pelican Bay at Del Norte, Corcoran State Prison and the California Correctional Institute at Tehachapi, according to the Huffington Post.

The state has been under a federal court order since May to reduce the prison population by 30,000 to 110,000, a level that is still 137.5 percent of the state’s prison capacity, according to the New York Times.

The striking inmates, who are mostly housed in solitary confinement, or security housing units (SHU), are demanding that correction officials implement individual punishment instead of group discipline, abolish a policy that requires inmates to reveal incriminating information on gang activity as a condition of release from an SHU, and discontinue long bouts of solitary confinement, as recommended by the federally-appointed U.S. Commission on Safety and Abuse in Prisons, according to the Huffington Post. Protesters also say they want better food and sanitary conditions and more education opportunities.

“We believe our only option of ever trying to make some kind of positive change here is through this hunger strike,” Todd Ashker, a Pelican Bay protestor, told The New York Times. “There is a core group of us who are committed to taking this all the way to the death if necessary.”

Prison spokeswoman Thornton told the Times that the strike is being led by gang members.

The hunger protest comes several months after inmates in Georgia prisons protested conditions by refusing to work or leave their cells.