 By late August 871, 'Ali ibn Muhammad decided that Basra had been reduced to the point where a full-fledged assault was possible, and began preparing for an attack.A message was sent to 'Ali ibn Aban, recalling him from Jubba and ordering him to proceed against the city, while Yahya ibn Muhammad, who was then conducting the blockade, received a similar command.A man was sent to the nearby Arab tribes in an effort to convince them to join the attack; many of them agreed to do so and a second man was sent to train them for the operation.