Media digest

British sub joins search for jetliner

A British submarine has joined the search for the missing Malaysian airliner in the southern Indian Ocean, a sign that authorities are gearing up to scour the seabed for the "black box" flight recorders even though no plane debris has been found.

The deployment of HMS Tireless bolsters a multinational search for the missing Boeing 777 that has so far relied on a combination of satellite and radar data to look for wreckage floating in an area of sea the size of Italy.