Twelve boys and their football coach who were rescued after being trapped for over a fortnight in a flooded Thai cave spoke publicly of their incredible ordeal for the first time yesterday at a press conference beamed around the world.

The "Wild Boars" team members looked healthy and happy as they answered questions about the nine days they spent in the dark before being discovered by members of an international rescue team.

A packed crowd greeted the youngsters -- some of whom were trapped in the cave for 18 days -- after they were discharged from hospital in Chiang Rai, and watched as they played with footballs on a small makeshift pitch before taking their seats.

"It is a miracle," Wild Boars footballer Adul Sam-on, 14, said of the rescue, as the boys were gently quizzed about their terrifying experience.

The team had no food at all until they were found deep in the complex, surviving only on water that dripped down the side of the cave.

"We tried to dig out as we thought we cannot only wait for authorities to get us," coach Ekkapol Chantawong told reporters.

But doctors said all 13 were in good physical and mental health after recuperating in hospital.

The briefing was tightly controlled, with experts warning of possible long-term distress from the more than two weeks they spent trapped inside a cramped, flooded chamber of the Tham Luang cave in northern Thailand.

The public relations department in Chiang Rai solicited questions from news outlets in advance, which were forwarded to psychiatrists for screening.