France's largest prison guards union says it has accepted a new plan to improve working conditions, a move that could end a nationwide strike sparked by a series of assaults.

The plan was presented Thursday by Justice minister Nicole Belloubet, who proposed boosting security to protect guards from the most dangerous inmates, and offered better rates of pay.

UFAP-UNSA said in a statement on Friday it will sign the proposed plan, which would allow for 1,500 radicalized convicts to be housed in special units.

The protest, the largest of its kind in years, entered its 12th day Friday. The blockades started after a radicalized inmate attacked three guards with a knife at a high-security prison in northern France on Jan. 11. More attacks have since been reported in about a half-dozen prisons.