Government cyber security agency CERT NZ says a distributed denial of service (DDoS) attack is targeting a number of New Zealand organisations.
"CERT NZ is aware of a DDoS attack targeting a number of New Zealand organisations. We are monitoring the situation and are working with affected parties where we can," CERT NZ's website says.
A DDoS attack involves the use of multiple connected online devices to overwhelm a target website with fake traffic.
This follows a series of internet outages for customers of Kiwibank, and ANZ, and website problems elsewhere including for NZ Post.
Last Friday customers of internet provider, Vocus NZ, were kicked offline after a cyber attack on one of its customers. Vocus owns Orcon, Slingshot and Stuff Fibre.