Officials from the Krabi Harbour Office on Monday joined with forensic police and related officials to inspect the scene where the Sunday explosion of a speedboat injured 16 tourists and boat staff heading from Phuket to Koh Phi Phi.

The police want to charge Pheu Thai’s key figure, Watana Muangsook, and three more people for planning to instigate unrest ahead of the August 25 court verdict ruling in the case of former prime minister Yingluck Shinawatra.