The questioning followed searches held at two places in Coimbatore and one place in Alappuzha in Kerala based on warrants issued by an NIA court in Kochi, NIA sources said.
The NIA has seized documents during the searches, the sources said in Kochi.
A few persons were being questioned at Coimbatore and Kochi, the sources said without elaborating further.
Some persons with suspected links to IS were arrested at Kanakamala by the NIA then.
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The NIA sources today said no one has been newly arraigned as accused in the Kanakamala case and no arrests have been made so far in the latest action.
A report from Coimbatore last night quoting police had said two persons were questioned by NIA for allegedly supporting the IS on social media.
Based on posts on some social media platforms, NIA officials have zeroed in on the duo, who allegedly posted content on Facebook, WhatsApp and Twitter, supporting the activities of the IS.