- Special anti-truck-ram barriers are installed at the four roads leading into estate
- Three-foot-high modular barriers can be erected in seconds by police officers
- Gates can stop trucks weighing as much as 7.5 tons travelling at up to 30mph
- The barriers were all on stand-by today as the Queen attended a Sunday service
New anti-terror measures have been put in place around the Queen's Sandringham estate for the first time as several high-profile royals stay there for the festive season.
Special anti-truck-ram barriers have now been built at the four roads which lead to the Royal residence in Norfolk.
The three-foot-high modular barriers can erected in seconds by police officers in the event of a terror attack involving a heavy goods vehicle.
They have been designed by Belgium company Pitagone and can stop trucks weighing up to 7.5 tons travelling at up to 30mph.
The special barriers are fully adjustable and can be used on all types of terrain and, because of their modular design, they can be built very quickly.
The barriers were all on stand-by today as the Queen and other members of the Royal family attended the weekly Sunday service at Mary Magdalene Church.
Similar precautions have also been installed at the Queen's other residencies, including Buckingham Palace and Windsor Castle.
Police were waiting at each of the four roads, with the barriers blocking half the road, ready to be moved if needed.
It is believed that officers were equipped with stinger devices to lay across the road and puncture the tyres of any vehicles which did not stop.
The extra precautions which have not been seem at Sandringham in previous years are thought to have been brought in over fears of a potential terrorist attack on the 20,000 acre estate in Norfolk.
It is believed that the barriers were set up in the morning on four roads approaching 16th century St Mary Magdalene church at Sandringham.
An estimated 3,000 people watched the Queen arrive for the morning service, accompanied by a lady in waiting in her maroon-coloured Bentley.
The crowd was one of the biggest ever seen at a Sunday church service with many people admitting that they had hoped to see The Duchess of Sussex or the Duchess of Cambridge.