The remains of six Holocaust victims murdered at Auschwitz have been buried as the UK’s chief rabbi urged an end to an “increase in antisemitism”.

About 50 Holocaust survivors joined hundreds of other members of the Jewish community at the United Synagogue New Cemetery in Bushey, Hertfordshire, for the funeral service.

During an address, Ephraim Mirvis warned antisemitism was on the rise and unchecked hate speech could “easily be translated into hate crime”.

The ashes and bones of the six unknown victims were sent from Auschwitz to the Imperial War Museum in London in 1997. Scientific tests later discovered they were the remains of five adults and one child, but nothing else is known about them.

The funeral service was the first for Holocaust victims to be held in the UK. After a 40-minute service, a small coffin, which held the remains of all six victims, was carried to its plot where it was buried with earth from Israel. The survivors and other mourners lined up to throw earth on to the coffin.

Rabbi Mirvis said the funeral was a reminder “to confront all forms of racism and discrimination”.

He added: “The message that you convey through the presence of your remains before us today is that if antisemitism exists, and it goes by unchecked, then hate speech can easily be translated into hate crime.

“And when antisemitism is allowed to thrive, some people can do anything and some people can reach the lowest end of human conduct.”

James Brokenshire, the communities minister, who attended the ceremony, said afterwards: “We must continue to challenge racism, antisemitism and bigotry and where hatred can lead. That’s why I think this has been such a unique occasion to be able to give some dignity, some respect, some acknowledgement to those six souls who lost their lives in the Holocaust.

“And how, I hope, it will bring people together and underline that message of never again, never forget and that none of us can simply stand by the side and allow this to happen.”

A Holocaust survivor, Agnes Grunwald-Spier, an author and historian born in Budapest in 1944, said she believed her grandfather was murdered at Auschwitz but her family had never been able to find the truth.

She said: “In a way, these people represent all those millions who have no grave and whose families can’t mourn them properly because they don’t know what happened to them.”

The remains were returned by the IWM to the Jewish community after a stocktake of its Holocaust material last year.