RAMALLAH: Ayman Nasser, a researcher for the Palestinian prisoners' rights organization Addameer, will spend at least nine more days in an Israeli military detention center, Addameer reported in a statementon Tuesday. This is the sixth consecutive extension of Nasser's detainment, and Addameer reports that he has been interrogated for an uninterrupted period of 31 days. “When not in interrogation Ayman continues to be held in isolation, in a windowless cell (1.5 meters by 2 meters), with a light continuously on and cold air continuously coming from the air," the statement read. “Addameer calls on the international community to intervene immediately with the Israeli authorities to ensure Ayman's release, in particular the United Nations Special Rapporteur on the Situation of Human Rights Defenders.” Nasser was arrested on October 15 and initially placed under a 25-day interrogation sentence. Last month, Human Rights Watch condemned Israel's “harassment" of Adameer employs. HRW director Sarah Leah Whitson added, “It's deeply ironic that Israel is arbitrarily detaining a researcher who has documented administrative detention, and violating the rights of the head of a human rights group." Addameer says that Nasser, as a prisoners' rights worker, qualifies as a human rights defender under international law, and his prolonged detention without charge violates the United Nations Universal Declaration of Human Rights.