The UN human rights chief Saturday strongly denounced the "sharp rise in hatred globally" since the war between Hamas and Israel began on October 7.

Volker Turk said in a statement he was "disgusted" by the surge in cases of anti-Semitism, Islamophobia and other hate-speech, both online and offline.

"The impact of this crisis... has sent shockwaves across every region, dehumanising both Palestinians and Jews," Turk said.

"We have witnessed a sharp spike in hate speech, violence and discrimination, deepening social fractures and polarisation... I have heard from both Jews and Muslims that they don't feel safe, and it saddens me," he added.

Israeli troops have encircled Gaza's largest city, trying to crush Hamas in retaliation for October 7 raids that Israeli officials say killed an estimated 1,400 people inside Israel, most of them civilians.

The health ministry in Gaza, run by Hamas, says nearly 9,500 Gazans, mostly women and children, have been killed in the Israeli military campaign.

Turk said that around the world "Islamophobic and anti-Semitic harassment, attacks and hate speech have multiplied, including in the context of protests relating to the conflict".

He said homes and religious buildings had been defaced with threatening symbols along with other images and messages "meant to frighten and provoke hate".

The United Nations high commissioner for human rights also hit out at "inflammatory, toxic and hateful rhetoric" used by political leaders.

"The torrent of hateful language being used, including on social media, is abhorrent," he said.

Turk said "evil words have been accompanied by vile deeds", which he blamed on the "vicious language" emanating from the streets and from politicians.

Turk also voiced concern about undue restrictions on protests over the conflict, saying nations often cited risks to national security or the glorification of terrorism to justify such action.

"In some cases we have seen blanket or disproportionate restrictions on assembly predominantly in the context of pro-Palestinian protests," he said.

Turk insisted that any restrictions on peaceful assembly had to be proportionate and based on law.

Israel's unrelenting offensive against Hamas battled on into its fifth week with no sign of slowing Saturday, as US Secretary of State Antony Blinken met Arab foreign ministers in search of a diplomatic opening to ease the crisis.