THE National Trust will step up security after neo-Nazis conducted rituals at its historic sites.

A far-right group calling itself Woden’s Folk has carried out masked torchlit gatherings at a World Heritage Site in Avebury to and carved swastikas into trees at the Neolithic burial chamber Wayland's Smithy near Uffington.

The former is owned by the Swindon-based National Trust and the latter is managed by the trust on behalf of Heritage England.

Neo-Nazi organisation Combat 18 and the now-banned terror organisation National Action attended one of the group’s rituals at the landmarks.

A spokesman for the National Trust said that it had been aware of some far-right activity at Avebury, home to the world's largest prehistoric stone circle, and reported all concerns to the police but had no knowledge of the burial chamber rituals.

The spokesman added that it does not "condone, support or encourage any non-peaceful, antisocial or illegal activities at any of our places" and admitted that little could be done to improve safety at Avebury because it would "not be feasible to fence the stones off ".

A Daily Telegraph reporter went undercover to infiltrate the group and notify the trust of its actions, which prompted promises from the trust to step up security at the Uffington site.

The reporter heard from the fair-right group's founder, who calls himself Wulf Ingessunu, that the neo-Nazis held rituals at the Smithy more times than he could remember. Mr Ingessunu has written several blogs full of racist ideology that push for the introduction of "Aryan laws".

In one, he wrote: "We shall leave the political struggle on the streets of England to those brave young men and women who have taken up that struggle against overwhelming odds - ours is a religious struggle.

"But as you take back the streets of England, so shall we take back these ancient and holy sites around rural England."

The group calls itself Odinist, the same ancient Norse religion worshipped by terrorists Anders Brevik, who killed 77 people in Norway in 2011, and Brenton Tarrant, who shot dead 51 people in the Christchurch massacre in New Zealand earlier this year.

Former National Action member Garron Helm, who was jailed for sending anti-Semitic hate messages to MP Luciana Berger, appears masked and holding their flag on the Woden's Folk group's website.