Four Thai and one Myanmarese nationals were detained after their boat was stopped by ICG ship 'Akkadevi', about 40 nautical mile south east off the coast on September six.
The foreigners did not have any valid document. After a search some arms and ammunition were found in the boat, they said.
The boat was brought to Diglipur on September seven and the foreigners were handed over to police for interrogation, the spokesman said.