(AFP) - Mourners and leaders around the world on Monday voiced horror and a desire for peace at tearful memorials remembering the unprecedented October 7, 2023 Hamas attack on Israel that sparked a year of devastating war in Gaza.

People from Sydney to Rome and Warsaw to Washington grieved for those killed and urged freedom for those taken hostage one year ago, while rallies also called for peace in the Palestinian territories.

Protesters rallied in India's capital New Delhi and chanted "Free free Palestine" and pro-Palestian demonstrations were expected in the Netherlands.

The Hamas onslaught left 1,205 dead on the Israeli side, mostly civilians, according to an AFP tally based on the latest official Israeli figures.

Some 251 people were captured and taken as hostages to the Gaza Strip by militants, of whom 97 are still held captive in the coastal territory, including 34 the Israeli military says are dead.

According to the health ministry in Hamas-run Gaza, 41,909 people, the majority civilians, have been killed since the start of the war. The figures have been deemed to be reliable by the United Nations.

- 'Dark day' for Israelis, Palestinians -

Leaders from around the world condemned the deadliest in Israel's history.

"Let us bear witness to the unspeakable brutality of the October 7 attacks but also to the beauty of the lives that were stolen that day," US President Joe Biden said.

"History will also remember October 7 as a dark day for the Palestinian people because of the conflict that Hamas unleashed that day," he added.

Italian Prime Minister Giorgia Meloni, during a speech at the Great Synagogue in Rome, said "Let us not forget the inhumane aggression perpetrated a year ago by Hamas."

Japan's Foreign Minister Takeshi Iwaya "unequivocally condemned" the Hamas attacks on Israel but said his nation was "gravely concerned" by the humanitarian situation in the Gaza Strip one year on.

"Japan is seriously concerned about the rising tensions beyond Israel and the Gaza Strip throughout the Middle East region, including the West Bank, Lebanon, the Red Sea and the Gulf of Aden, and Iran," he said.

- 'Until they come home' -

Members of Australia's Jewish community gathered in Sydney for a vigil, where many held Israeli flags and lights in the shape of candles.

"Today is very emotional day," said 48-year-old Zack Shachar, whose cousin Naama Levy was taken hostage on October 7.

"In the last year, we participated in any event, we read the names of the hostages every week in a different place in the city, and we will continue to do it until they all come back home."

One hostage who did not make it home alive was Polish-Israeli Alex Dancyg and on Monday his family inaugaurated a plaque in his memory in Warsaw.

"We need to come here to (remember) my father, but also to put again the hostages on the agenda because that's the important thing now," said Yuval Dancyg, Alex Dancyg's son.

"We also still have one (hostage in captivity), our uncle. He's still in there. We're still in the situation," he added.

- 'Everyday people are dying' -

In New Delhi, around 150 protesters gathered in a peaceful rally to support the Palestinian people.

"Every day people are dying, they don't have food, they are starving," said social activist Bhavna Sharma.

Sharma, 52, carrying a placard that read "Stop the massacre", said she condemned India's support of Israel, including sales of arms.

"Why are we sending arms to Israel?" she said. "Why are we supporting Israel in any way?"

Saba Dave, 29, a development consultant, said she took part in the rally because she wanted peace.

"We were always against violence, so to continue that tradition of anti-violence, I am here," she said.

© Agence France-Presse