More than 1,000 cigarettes have been seized from an ice-cream van in Carrickfergus, customs inspectors said.
Around 1,200 cigarettes and a vehicle were taken away after officials swooped last Saturday at the Co Antrim seaside resort.
Mike Connolly, an assistant director at revenue and customs, said: "The unregulated sale of illegal cigarettes from an ice-cream van is of particular concern, where children would often be the main customer."
In a busy four days for officials, 9,300 litres of laundered fuel along with documentation relating to a further 60,000 litres of smuggled fuel were seized during separate operations across Northern Ireland.
A total of 341,200 cigarettes were seized, of which 40,000 were counterfeit.
Last Friday a van carrying five containers holding 5,000 litres of suspected laundered fuel was intercepted at Ballygawley in Co Tyrone as well as a curtain-sided lorry, transporting 1,300 litres of fuel in Co Londonderry. On the same day Her Majesty's Revenue and Customs (HMRC) officers seized 300,000 smuggled cigarettes from a property in Meigh, south Armagh.
Mr Connolly added: "The sale of illicit fuel and cigarettes not only drains vital revenue from public services but also poses a risk to the wellbeing of our communities."
He said: "... The dangerous practice of transporting fuel in unsuitable large bulk containers, which puts everyone in the vicinity at risk, should make these activities unwelcome within any neighbourhood."
On Saturday police officers intercepted a car in Newtownhamilton, Co Armagh, and found 40,000 counterfeit cigarettes.
And on Monday, a van carrying 3,000 litres of laundered fuel in containers was discovered at Banbridge, Co Down. During follow up searches of business premises in Randalstown, Co Antrim, a van running on red diesel was seized along with business records of a further 60,000 litres of smuggled fuel.