"We arrested 65 of them over the last month. Five of them later came to be released due to lack of evidence," police spokesman and Superintendent Ajith Rohana said.
They were nabbed for their terrorist financing and related activity aimed at reviving the LTTE, he said, adding that 10 of them were women.
The 60 are currently being detained in gazetted detention centres of the government. "They have access to all the facilities under the law," Rohana said.
Last month, the government announced a list of designated terrorist groups and over 420 individuals allegedly engaged in terror financing.
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The 16 listed organisations included the LTTE and several key Tamil diaspora groups such as the Global Tamil Forum and the British Tamil Forum.
The diaspora groups are being described as the fronts for the LTTE in the Western world and seen as playing a key role in influencing the governments of countries like the US and the UK.
Since the end to the conflict, Sri Lanka rehabilitated at least 11,000 LTTE members who had surrendered at the final battle.
Up to 40,000 Tamil civilians were killed at the end of the nearly three-decade-long separatist war, rights groups and experts have said.