The alleged attacks had caused "unrest" in the community, he said.
"We want to reiterate our public safety messages which includes keeping to well-lit areas where possible, keeping your cellphone close, and ensuring you remain alert and aware of your surroundings.
"We really appreciate the support from the public, as it is their information and willingness to assist us that has helped us get this far in our investigations."
Police are still seeking information in regards to the other alleged attacks, which have taken place in Napier Hill, Taradale, and Havelock North.
They urged witnesses or people with information to call 06 211 3872.
Information can also be given anonymously to Crimestoppers on 0800 555 111.