Police have arrested 78 people inside Christchurch's central city red zone since the February earthquake.
The number of arrests was highest in May, when 18 people were detained for being inside the cordon without authorisation.
Central City Area Commander Derek Erasmus says the red zone remains a very dangerous place to be in and is only open for demolition work and other official business.
Mr Erasmus says many people found in the zone have been drinking alcohol.
The maximum penalty for breaching the cordon is a $5000 fine or up to three months' imprisonment.
