The UN’s human rights rapporteur in the Palestinian territories accused Israeli security forces of using excessive force against Palestinians, and called on Israel to investigate and prosecute perpetrators, Reuters reported.

“The upsurge in violence is a grim reminder of the unsustainable human rights situation in the Occupied Palestinian Territory and the volatile environment it engenders,” Makarim Wibisono said in his final Human Rights Council report.

Wibisono tendered his resignation from the position as special rapporteur on human rights in the West Bank and Gaza Strip last month. He effectively steps down at the end of March after starting in the position in June 2014.

He said in his resignation letter that his “efforts to help improve the lives of Palestinian victims of violations under the Israeli occupation have been frustrated every step of the way” because Israel didn’t give him access to the Palestinian territories.

Wibisono told the Human Rights Council Thursday that the Palestinian violence that’s raged since October came amid Israel’s construction of “illegal” West Bank settlements. He called Israel’s blockade of the Hamas-run Gaza Strip, designed to prevent the import of weapons by the terror group, a “stranglehold” and “collective punishment.”

Some 30 Israelis have been killed in a wave of near-daily stabbing, shooting, and car-ramming attacks by Palestinians since October. More than 160 Palestinians have also been killed, most of them in the act of attacking Israelis and others in clashes and demonstrations.

He also denounced Israel’s imprisonment of hundreds of Palestinians under administrative detention, calling it inconsistent with international standards.

“The government of Israel should promptly charge or release all administrative detainees,” he said.

The Foreign Ministry dismissed the UN observer’s report as reflecting “the one-sidedness of the mandate and its flagrant anti-Israel bias.”

“It is this one-sidedness which has made the rapporteur’s mission impossible to fulfill, hence his resignation,” Foreign Ministry spokesman Emmanuel Nahshon said.