The boats -- "dhows" -- had been under aerial surveillance and naval ship had been sent to probe them and neutralise if necessary, said Rear Admiral Sudhir Pillai, Flag Officer Commanding, Goa Region (FOGA).
The three small boats were spotted yesterday morning. "We had received inputs from a merchant ship about the suspected activities. Navy's IL-38, a maritime surveillance aircraft, spotted them and we have kept a constant watch on them," he said.
"We have been keeping watch on them for the last 24 hours and sent a naval vessel to neutralise them."
The Indian navy had also asked merchant ships to steer clear of the spot, he said.