Smoking is now banned in public places across the UK.
England's fell into line with Ireland Scotland and Wales at 6am.
There is a fine of €50 for anyone found infringing the new regulations.
Businesses caught flouting the law face fines of up to €2,500.
COMMENT RULES: Comments that are judged to be defamatory, abusive or in bad taste are not acceptable and contributors who consistently fall below certain criteria will be permanently blacklisted. The moderator will not enter into debate with individual contributors and the moderator’s decision is final. It is Belfast Telegraph policy to close comments on court cases, tribunals and active legal investigations. We may also close comments on articles which are being targeted for abuse. Problems with commenting? email@example.com