An Israeli prisoner at Hadarim Detention Center in central Israel has been arrested for sending a death threat to Prime Minister Binyamin Netanyahu.The 22-year-old prisoner was apparently angry at the prime minister's decision to release Palestinian security prisoners. He then sent Netanyahu a letter containing a death threat, prompting his arrest. According to the Israeli media, the prisoner was found to be in possession of more than one self-styled knife, commonly known as "shivs." According to Israel Radio, the prisoner identifies with the extreme Right and has been implicated in the past in 'price tag' activity, as well as issuing threats against Peace Now activists.The cabinet earlier this month voted to free 104 Palestinian prisoners classed as having "blood on their hands", as a goodwill gesture toward Palestinian Authority President Mahmoud Abbas as the two sides embarked on fresh peace talks after three years of stagnation. The first group of 26 prisoners were freed on August 13. Of that number, 11 were sent to the West Bank, and the others to the Gaza Strip.