Pop group Madness were unnerved when they performed on the roof of Buckingham Palace for Queen Elizabeth II's Diamond Jubilee show, as they were surrounded by crack shot cops touting sniper rifles.

The British band was invited to sing its hit track Our House atop the royal residence in London as part of the celebratory concert in June (12) but the high security levels at the event put them on edge.

Guitarist Chris Foreman insists he was nervous enough about the performance and became even more jittery when he saw the roof was lined with snipers ready to take out any potential terrorist in the crowd below.

Foreman tells Seven magazine, "We've got this armed police guard, and I was a bit on edge - until they asked to have their photo taken with us. But while we played, they had snipers on the roof, to the left and right of us."