Latest: Sound detected in search for missing submarine 'consistent with an explosion'

Update 2.50pm: Argentina says a sound detected in the search for a missing submarine with 44 crew members on board is consistent with a non-nuclear explosion but say that there is no evidence of an attack.

Navy spokesman Enrique Balbi said the relatives of the crew have been informed and that the search will continue until there is full certainty about the fate of the ARA San Juan.