MAE SAI, Thailand - The official heading the operation to rescue 12 boys and their soccer coach from a cave in northern Thailand says the operation is going 'better than expected.'

Chiang Rai provincial acting Gov. Narongsak Osatanakorn made the comment at a news conference Sunday evening after rescuers extracted four of the boys from the cave where they had been trapped for more than two weeks. Narongsak said the four were then taken to a hospital. Their condition was not immediately clear.

Narongsak said the weakest have been taken out first, and the next phase of the operation would start in 10-20 hours.

He said that 13 foreign and five Thai divers were taking part in the rescue and that two divers would accompany each boy as they're gradually extracted.