Two of the five injured were taken to hospital following the incident at Horse Guards Road in central London on Saturday.

Crowds were watching the rehearsal, ahead of the full event on 2 June for the Queen's Platinum Jubilee celebrations, when suddenly one stand gave way just before 11am and part of a second stand collapsed shortly afterwards.

Kyle Skeen and his wife Jen were in the audience with their three young children when they saw the stand collapse just a few rows in front of them.

They also shared pictures of a gap in the floor due to the stand breaking, before the crowds were then evacuated and paramedics arrived.

Speaking to Sky News, Mrs Skeen described the crowds' shock as the floor of one of the stands fell through without any warning.

She said: "When the royal carriage arrived during the rehearsal, everybody in the stands stood up. But almost immediately that part of the stand fell through and a woman fell down.

"To make matters worse, another woman was left dangling over the gap in the stands and was gripping onto the seat to avoid falling through as well.

"Everyone was in shock as they were wondering what happened and there was silence from inside the hole in the stand, so people didn't know if the woman was okay.

"It took a while for emergency services to get there - however, we soon heard the paramedics talking to the woman from inside and helping the other woman.

"Shortly after, the national anthem started playing, but this time people were reluctant to stand up from their seats in case it happened again.

"My children were shaken up by what had happened and we didn't really want to stay much longer after that."

Two parts of the viewing stand 'gave way'

The ceremony, which involves a parade by the Household Division and Horse Guards, was stopped as the crowds were evacuated by the emergency services.

An Army spokesman said two parts of the viewing stand "gave way" and that work was under way to determine the cause of the incident.

They added: "The emergency services were called to assist those who were injured and the remaining crowds were safely evacuated from the stands.

Read more:
Eight new cities named as part of the Platinum Jubilee celebrations
Six-minute flypast featuring Red Arrows, Spitfires and Hurricanes to follow monarch's birthday parade

"Safety is our number one priority and we are urgently working with our partners and relevant organisations to understand what happened and make sure it doesn't happen again."

In a statement, the Ministry of Defence added: "We are supporting the emergency services following an incident on the Horse Guards parade square.

"It would be inappropriate to comment further at this time."

Sky News has contacted Buckingham Palace for a comment.