Government today decided to declare Islamic Research Foundation floated by preacher Zakir Naik as an unlawful organisation under Unlawful Activities (Prevention) Act, Sources said, stating that the Cabinet has banned the NGO for five years and asked security agencies to keep a strict watch on its activities.<br/> <br/>Few months ago, Naik came in the centre of controversy following reports that militants involved in Dhaka terror attack were inspired by his provocative speeches. Since then, there has been demands for action against the preacher.