Most of these fishing boats lack systems to gauge geographical positions. (Representational)

The Sri Lanka Navy has arrested at least four Indian fishermen and seized a fishing trawler for allegedly poaching in the country's territorial waters.

The Navy arrested the fishermen when they were engaged in illegal fishing practices in Sri Lankan territorial waters in the sea area off the Kovilam Lighthouse on July 24, the Navy said in a statement on Wednesday.

Four Indian fishermen, from Tamil Nadu, were arrested for allegedly breaching the International Maritime Boundary Line (IMBL) and illegally fishing in Sri Lankan waters, Colombo Page reported.

The trawler used by them was brought to the naval base SLNS Elara in Jaffna.

After a medical test, the fishermen will be handed over to the Assistant Director of Fisheries in Jaffna for further investigation, it said.

The Navy media unit said that as a result of continuous patrols conducted by the Sri Lanka Navy, the number of Indian fishing trawlers entering Sri Lankan waters has significantly reduced.

In January 2018, Sri Lanka increased by over 100 times the fine on foreign vessels to deter them from fishing in its waters, amid the dispute over the frequent entry of Indian fishing trawlers into the country's maritime territory.