A Doomsday Clock, which symbolises the current threat of global annihilation, has been moved 30 seconds closer to midnight by scientists.

The countdown was established in 1947 by a group of experts who were working on the Manhattan Project to design and build the first atomic bomb.

They wanted a simple way of demonstrating the danger to Earth and humanity posed by nuclear war.

The clock was running at three minutes to midnight, where 00.00 represents the end of humanity.