Transcript for Royal Family Defiant in Face of Foiled Terror Plot
Keeping calm and carrying on the queen and royal family leading the country's most somber day in the wake of the foiled terror plot that authorities fear. Could have hit very close to hello. We are to believe what has been released that attack. Was to be focused on members of the British government and senior members of the royal fan Scotland George arresting four men as part of a quote. Ongoing investigation into its slimmest relate to terrorism. Just days before the symbolic event the men are still in custody being interrogated. So security was stepped up around London with a ring of steel around the royals. The screening the rooftop surveillance as being carried out the days if not weeks. Despite the fears of a terror attack and amid heightened security and her majesty and her family undeterred. To pay tribute to the full it since World War I. Prince William laying a wreath case observing the commemoration. From the balcony above. Away from London Prince Harry no stranger to danger himself secretly returning to Afghanistan. For a quick trip to represent the queen and pay his respects. A show of defiance marked by applause and the crowds. 'cause thank you to the queen and the royal family for bravely carrying out their duties. Despite the terror threats. A terrifying warning this morning security chiefs reportedly saying the scale of terrorist activity is so great. Then it's hot here is almost inevitable in the coming months. MI five in Scotland Yard believe they have stopped three plots in London in the loss for months with some of the suspect. And ledges be ready to strike at terror threats is very high in the UK. Llama Hasan ABC news London.
This transcript has been automatically generated and may not be 100% accurate.