The recent event in Ketziot prison in which Hamas inmates stabbed prison guards was an act of terror, Israel Police said on Wednesday.
The meaning of the decision is that the investigation will not be led by prison authorities but by Lahav 433, the unit that oversees serious and international crimes.
One of the suspects, who was allegedly involved in the preparations to the attack, was ordered to remain in police custody until Tuesday.
"We will not allow nor accept attempts to harm the men and women in uniform," The Police spokesperson said. "We are committed to act and investigate this grave case."