The Navy spokesman said that the arrests were made off the coast of Negombo, the west coastal fishing town.
The boat and those arrested are being taken to Mutwal, north of Colombo for further procedural action, the spokesman said.
During the last two weeks, over 600 people have been arrested for involvement in illegal migration scams, police spokesman Ajith Rohana said.
Last week, a Sri Lankan who was under arrest for illegal entry to Australia was deported.
"This was an example that those who take the illegal routes for migration are not safe and would be deported", Rohana said.
Sri Lanka has urged Australia to turn back the boats carrying Lankans illegally. Australia have not responded positively to the request, Lankan authorities claim.