At least four people have been killed in landslides in southern Thailand, bringing to 15 the death toll in the flood-battered region.

A Krabi province official says another 10-20 people are missing in the landslides from late Tuesday night. Some seven villages were affected by the slides, three of which were inaccessible Wednesday morning.

Vittayen Muttamara says 716,110 persons have been affected by floods in eight southern provinces. The Thai Navy has dispatched three vessels to help evacuate tourists from resort islands such as Koh Samui.

Prime Minister Abhisit Vejjajiva visited the region Wednesday morning and ordered residents evacuated from all areas at risk.