text: The case of the missing planes was raised when PM David Cameron met Burmese President Thein Sein.
  A Downing Street source said it was "hoped this will be an opportunity to work with the reforming Burmese government".
  The exact location of the planes is unknown.
  The planes were buried in 1945 by the RAF amid fears that they could either be used or destroyed by foreign forces, but in the intervening years they have not been located.
  At the time they were unused, still in crates, and yet to be assembled.
  Until a general election in 2010, Burma was ruled for almost half a century by a military junta.
  It has been reported that experts from Leeds University and an academic based in Rangoon believe they may have identified the sites where the craft are concealed using sophisticated radar techniques.
  On Friday, officials said President Thein Sein was "very enthusiastic" about the prospect of finding and restoring the planes.
  A Downing Street source said: "The Spitfire is arguably the most important plane in the history of aviation, playing a crucial role in the Second World War.
  "It is hoped this will be an opportunity to work with the reforming Burmese government, uncover, restore and display these fighter planes and get them gracing the skies of Britain once again."
target: British and Burmese authorities could work together to find 20 Spitfires buried in Burma at the end of the World War II, officials say.