Thai rescuers on Thursday said they may be prodded into a complex extraction of 12 boys and their football coach from a flooded cave if forecast rains hammer the mountainside and jeopardise the rescue mission.

Thirteen sets of diving equipment have been prepared for the team, who have endured 12 nights underground in the Tham Luang cave complex. Water is being pumped out from the deluged cave round-the-clock, reducing the flooding by one centimetre an hour.