They also pelted stones at the fishermen before driving them away
The seven, part of groups of fishermen who put out to sea from Rameswaram in TN, have been taken to Talaimannar in northern Sri Lanka.
The Lankan naval personnel cut fishing nets of about 70 boats and pelted stones and bottles forcing more than 2,000 fishermen to flee and return to the shore on Thursday morning.
Fishermen from Rameswaram were attacked near the international maritime boundary line, allegedly by Sri Lankan navalmen who threw stones at their boats damaging about 50 of them, officials said on Tuesday.
The Lankan Navy also seized three boats.
With this, the number of fishermen arrested for allegedly fishing in Lankan territorial waters have gone up to 44 since July 3.
Fifty-three fishermen, including 30 from Rameshwaram, were arrested by the Sri Lankan naval personnel off Talaimannar and Jaffna early Thursday morning, Fisheries Association officials said.
If the fishermen were not allowed to fish in their traditional areas (Katchatheevu), they would be left with no other alternative except to commit suicide like distressed farmers, they said.
The Sri Lankan Navy has arrested another 11 Tamil Nadu fishermen late on Wednesday night, hours after they apprehended 36 fishermen hailing from a village in Pudukottai district while fishing near Neduntheevu and Katchatheevu islet, a fisheries department official said.