LONDON, United Kingdom - A UK interfaith coalition comprising religious, political and civic leaders, as well as grieving relatives of some of those killed in the Israel-Hamas war, held a vigil Sunday in London.

Hundreds gathered mid-afternoon in wet and frigid conditions opposite Prime Minister Rishi Sunak's Downing Street office and residence to "give a voice to the majority of the public who stand against hate", organisers said.

The grouping, Together for Humanity, aimed to highlight its nascent movement against rising anti-Semitism and anti-Muslim hate with the event, dubbed "Building Bridges".

It was spearheaded by Brendan Cox, the widower of murdered British lawmaker Jo Cox, and supported by Archbishop of Canterbury Justin Welby as well as a leading British rabbi, imam and peace activists.

Welby told the crowd it was time to "clean away anti-Semitism and Islamophobia", both of which have been on the rise in Britain since the war sparked by Hamas's unprecedented attack.

Hamas militants burst through Gaza's militarised border into Israel on October 7 and killed about 1,200 people, mostly civilians, while also taking around 240 hostages, according to Israeli authorities.

Israel's retaliatory military campaign has killed more than 15,500 people in the besieged Palestinian territory, mainly civilians and thousands of them children, according to the Hamas-run health ministry.

"We will not let anti-Semitism, Islamophobia have a role in our streets, our schools, our towns," Welby added.

Imam Monawar Hussain said "we stand united against all those who seek to sow hatred and division".

British-Israeli Magen Inon, whose parents were killed in Hamas's October 7 attack, was also among the speakers.

"Of course I'm angry," he said.

"What the terrorists really tried to kill is the possibility of people of different backgrounds and faiths to live in peace alongside one another," Inon added.

"The only possible revenge of my parents is to set aside fear and hate and to be hopeful that a better future is possible."

'Every year is worse'

Others at the vigil included Palestinian peace activist Hamze Awawde, who lives in Ramallah in the Palestinian Territories and has had relatives injured recently in the conflict.

He spoke of his grandfather, who 50 years ago "chose to fight and sacrifice himself, so his children and grandchildren would have a better future."

But "50 years on, every year is worse than the last."

With rain pouring down, those gathered observed a minute's silence in memory of the victims of the conflict, "whatever their origins".

Together for Humanity has emerged since Israel began bombing Gaza in response to the October 7 attack, which has prompted a spike in anti-Semitism in Britain.

At least 1,747 incidents were recorded between October 7 and November 29 by the Community Security Trust, whose role is to protect the UK's Jewish community.

Meanwhile, London and other UK cities have seen large-scale protests on recent weekends in support of Palestinians in Gaza, which have polarised public opinion and been blamed for stoking social divisions.

Ahead of the vigil, Cox, a father of two, said the "loudest and most extreme voices have drowned out the vast majority of the public" when it came to the conflict.

His wife was killed by a Nazi sympathiser days before Britain's contentious 2016 Brexit referendum, and he subsequently co-founded the Together Coalition charity.