The website for ANZ Bank is offline again, as it continues to deal with cyber attacks. 

ANZ was among a number of organisations hit by an attack, which took down the Inland Revenue, MetService, New Zealand Post and Kiwibank websites. 

Most of these sites are back online, but ANZ's struggle this morning indicates that the battle is ongoing. 

ANZ used its social media channels this morning to inform customers that it was working to rectify the outages. 

A statement yesterday from security agency CERT NZ said it was aware of a DDoS (Distributed Denial of Service) targeting a number of New Zealand organisations. 

"We are monitoring the situation and are working with affected parties where we can." 

A spokesman for the GCSB's National Cyber Security Centre said, "We are limited in any public comment we will make as we are aware that malicious cyber actors can follow what is reported publicly, and may change their behaviour based on media reporting of their activity. 

"DDoS attacks are not new, and most are repelled by organisations working with their service providers who are best placed to implement technical mitigations."