Health officials are working to contain a measles outbreak in Christchurch.
Four teenagers at Christchurch Boys' High School have caught the potentially lethal infection, with a fifth case suspected.
The boys are all in isolation at home. Their family and friends have also been told by authorities to stay home for several days unless they are immunised against the childhood disease.
Canterbury medical officer of health Cheryl Brunton is expecting more cases in the coming days.
"It is an outbreak of a highly contagious disease and we expect that there will be many more cases associated with this outbreak," she told Radio New Zealand.
"Just talking to the cases and their parents that we know about, we know that they've had contact with many other children."
