A plane carrying two Palauan police officers and their pilot is missing, and a Chinese fisherman is dead following a police operation to intercept a Chinese vessel in Palau waters.
The Pacific News Centre says officials suspected the vessel of fishing illegally in a conservation area, and only fired on it to try and get it to stop after pleas were ignored.
It also says once the fisherman spotted local authorities they then attempted to set the boat alight.
At least five Chinese fishermen were arrested and they face charges including "unlawful entry"; "illegal fishing"; and "conspiracy to commit unlawful acts".
Meanwhile, the missing plane was used in the operation to search for any other vessels that may have been in the area illegally.
Reports say on its return flight the navigational system failed, the pilot radioed that he had run out of fuel and was going to make a water landing. Then all contact was lost.
The U.S. Coast Guard has joined in the search for the three.