Nine people have been arrested in Queenstown after a three-month police drug operation.
Customs officials and members of the armed offenders squad swooped on houses in Queenstown, Glenorchy and Cromwell early on Tuesday morning.
Detective Graham Bartlett says two firearms were seized, along with a quantity of class A, B and C controlled drugs, including LSD and ecstasy.
Loud explosions were heard coming from a Frankton house at 4am, but Mr Bartlett says no shots were fired and the explosions were part of armed offenders squad tactics to gain entry to the house.
Four people will appear in Invercargill District Court on Wednesday on a variety of drug and firearms charges.
A further five people will appear in Queenstown District Court on Monday on drug charges.