Israeli authorities last week placed three Palestinian minors from East Jerusalem under administrative detention, a move rights group say is unprecedented in the city, as Israel heightens security measures amid a month of deadly violence.

On Oct. 19, Fadi Abassi, 17, and Mohammed Ghaith, 17, were arrested following dawn raids on their homes in the neighborhood of Silwan, according to Defense for Children International – Palestine.

Days earlier on Oct. 16, Kathem Sbeih, 17, was detained from his family home in Jabal al-Mukkabir, a neighborhood at the heart of current tensions which Israel earlier in the month sealed off from the neighboring East Talpiot settlement with concrete blocks and a wall.

The policy of administrative detention — which dates back to emergency laws under the British Mandate — came under intense scrutiny earlier this year following a 65 day hunger strike by Palestinian detainee Muhammad Allan to protest his detention without trial.

In April, the United Nations Human Rights Office explicitly criticized the policy following the detention without trial of Palestinian MP Khalida Jarrar, calling on Israel to end the practice once and for all.

Despite this, the policy — which relies on secret information withheld from the accused and their lawyers — has been widely implemented since the escalation of violence in East Jerusalem and the West Bank.

– Read More: Israel Expands Detention without Trial to Minors in East Jerusalem – Charlie Holye, Maan