LITTLE ROCK, Ark. (AP) — Arkansas’ governor called for additional safeguards at the state’s prisons on Friday after a string of violence that included three guards being assaulted by inmates and hospitalized a day earlier in separate attacks at two facilities.

Gov. Asa Hutchinson said he was greatly concerned by the incidents Thursday afternoon in which two guards were assaulted by several inmates at the Varner Unit hours after a guard was assaulted by a prisoner at the Maximum Security Unit in Tucker.

“The multiple incidences in the past few months of violence indicate there is a need for additional safeguards,” Hutchinson, a Republican, said in a statement released by his office. “I have met with (Department of Correction) Director Wendy Kelley and Board of Corrections’ Chairman Benny Magness, and I have asked Director Kelley for an action plan with options to address the problem and to ensure order and safety in the prison system. Director Kelley and her team have my full support as they address this challenge.”

One guard at Varner sustained a single, unspecified injury in Thursday’s attack, while another suffered multiple lacerations. Both have been treated and released from an area hospital, Department of Correction spokesman Solomon Graves said Friday. The guard attacked at the Maximum Security Unit sustained multiple injuries to the face and head and remained hospitalized. Several inmates at Varner who had barricaded themselves in a barrack after Thursday’s assault there were also hospitalized after officers used nonlethal force on them, authorities said.

The department has said the attacks appear to be unrelated.

The assaults follow two other disturbances at the Maximum Security Unit — also known as Tucker Max — in recent months. In August, several inmates held three guards hostage after snatching their keys and a Taser and a month before that, a guard fired warning shots into the air after two guards and an inmate were attacked there.