Giant Olympic rings have been unveiled at Heathrow Airport to welcome athletes and spectators to London.

The aluminium rings which measure 12 metres in width, the same as a double decker bus, have been installed in Terminal Five international arrivals where they will be seen by two million passengers travelling through Heathrow.

The rings were officially launched at a ceremony on Wednesday morning by former Olympian Mark Foster. He said: "I know first-hand the nervous excitement that every athlete feels when they arrive for the Olympic Games.

"The atmosphere is electric and often the airport is the first time we see fans and really feel the special buzz of the weeks to come. The rings will create a huge sense of excitement and be a great part of the welcome for everyone travelling through the terminal."

Entertainment for the ceremony was provided by the Band of the Irish Guards. Garrison Sergeant Major William Mott OBE, whose 30 foot portrait is displayed in Terminal Five, was also at the event.

The Olympic rings are meant to symbolise all five continents coming together. Giant rings are being installed at iconic sites all over the United Kingdom and have already been revealed in Edinburgh and Newcastle.

London 2012 chief executive Paul Deighton said: "The Olympic rings are an iconic symbol, inspiring athletes and uniting people around the world.

"To athletes they represent the culmination of thousands of hours of training and reaching the highest level in sport.

"As we welcome the world, these rings will excite and inspire visitors arriving at Heathrow."