"Terrorist attacks cannot destroy the values on which our societies are grounded - but laws and policies can," the UN high commissioner for human rights said.

Addressing the UN Human Rights Council, Zeid criticized policies implemented in Middle Eastern and African countries with extremist conflicts, as well as in Western countries that are reacting to terrorism and radicalization.

The Jordanian diplomat and rights expert pointed out that various anti-terrorism measures constituted human rights violations, including arbitrary detentions, mass surveillance, discriminatory police practices and restrictions on free speech.

"There is real danger that in their reaction to extremist violence, opinion-leaders and decision-makers will lose their grasp  of the deeper principles that underpin the system for global security which states built 70 years ago to ward off the horror of war," Zeid said.

Such policies fuelled resentment, opened rifts within societies and provided propaganda tools to extremist groups, he said.

Governments should instead implement narrowly targeted policies to pursue the terrorists and cut off their money and arms supplies, he said.

Zeid pointed out that many of the radicalized people who joined extremist groups such as Islamic State in Syria and Iraq were driven by inequalities and discrimination, and that governments must therefore tackle these root causes of extremism.

Among the measures he criticized, the UN rights chief highlighted US torture and detention policies for terrorism suspects.

"The orange jumpsuits of Guantanamo are a recruitment tool for

Islamic State and other groups," Zeid said, referring to the prisoner uniforms at the US detention centre where terrorism suspects have been held for long periods.

Zeid also criticized Egypt for reacting to violent extremism by cracking down on civil society, as well as Nigeria for human rights violations committed in the government's fight against Boko Haram terrorists.

--Sapa-dpa--