MH370: Missing plane search 'most challenging ever'
1 April 2014 Last updated at 15:24 BST
The search for missing Malaysia Airlines flight MH370 is the "most challenging" ever seen, the man responsible for co-ordinating the search from Australia says.
Air Chief Marshal Angus Houston also said that the search for the plane could take weeks.
The plane disappeared on 8 March as it was travelling from Kuala Lumpur to Beijing. It was carrying 239 people.
Search teams are scouring the southern Indian Ocean for signs of the plane.
Lucy Williamson reports.