Meanwhile, protesters are also gathering outside the American embassy in London calling for changes in US gun laws. It is one of 800 rallies in cities across the US and dozens of locations overseas that will take place at roughly the same time. Organisers say the protests will be a defining moment in the long-simmering debate in the US over gun-control legislation.

JONATHAN CORNEJO CAMPAIGNER "I think what the students have done at Parkland school has been amazing, they've come together at a very difficult time, and raised their voices and really taken control and changed the narrative around gun control in the USA. This is the beginning of a wide movement. It's global there's hundreds of events across the world. And obviously were here all standing with them, calling for sensible gun control across the UK, and Amnesty International is very proud to support this movement led by students."