A coronavirus cluster in Matamata is linked to a St Patrick's Day celebration, the Waikato District Health Board has confirmed.
There are now 23 residents from the small town confirmed to have Covid-19, and most have been identified as having attended the March 17 event, or having close connections to those who did.
"The public health team continues to work through the connections of those affected to ensure we continue to link our positive cases and discount true community transfer. Work to date identifies the original source to be linked to overseas travel," said incident controller for the health response in Waikato Leena Singh.
"With the alert level four lockdown now in effect, residents of Matamata can be assured that they are already undertaking the safest possible practice by isolating and should continue to follow the national guidance. To ensure they limit any further transmission people should avoid travel, wash their hands and practice social distancing.
"Please stay in your bubble as this is the most effective way to eliminate the virus."
Singh said any Matamata residents with symptoms of Covid-19 should contact Healthline or their GP and visit a community based assessment centre. They should inform the staff if they had attended the Redoubt Bar during the previous two weeks, or if they had close contact with anyone who had.
Any visitors to the town who had visited the bar on March 17 for the St Patrick's Day celebration who is now experiencing symptoms should also follow these steps.
Singh said it was important to know whether there has been spread beyond Matamata.
A testing centre is now being set up at the Matamata Civic Centre and is expected to begin operating from 3pm today.
All swabs taken from Matamata will undergo priority testing.
Residents are "a little bit concerned" at news of the cluster, the mayor said.
Matamata-Piako mayor Ash Tanner earlier said: "I think the feeling amongst the residents is that they're a little bit concerned, especially when the cases in a certain area are going up. I know a lot of them are ringing the Healthline."
He was aware of some of those people who had been referred on for testing.
"Hopefully they come back clear and then we can move on."
He asked everyone to "do their part" and stay at home to "ride this out".
"If we don't do it then the four-week period could extend. It wouldn't be ideal.
"We're all in this as a community together and we will all get through it as a community."
A spokeswoman for Redoubt Bar and Eatery Matamata said one of their staff members who had contracted the virus was "recovering well".
"Young and healthy seems to be the key," she said.
"We are just hoping for the absolute best result for our beautiful community. It's heartbreaking and scary on so many levels."
In an earlier post on Facebook, she said the virus was "insidious" and "awful".
"We have had a confirmed case of Covid-19 among our staff. We have been in daily contact with the district health board and have been reassured that everyone is doing what they should be now. Self-isolating and watching for symptoms," the post said.
"Our hearts go out to the other Matamata businesses who are in the same boat. You can't help but feel guilty even though we were operating according to all guidelines.
"We wanted to let you know as communication is key. We love our community and hope you are all keeping safe. Our family all well for now and thinking of you all."
The Horse and Jockey Inn also, "with heavy hearts", shut its doors a week ago.
"We are down but we are by no means out, and we very much look forward to coming back bigger and better," an online post said.
"We hope to reopen the doors as quickly as we've had to close them."
The Ministry of Health is now investigating seven clusters of the respiratory virus across the country.
These include Auckland's Marist College, which has 31 confirmed and five probable cases, and the World Hereford Conference, with 17 confirmed and two probably cases.
The clusters are:
• Marist College, Auckland - 31 confirmed cases, 5 probable
• World Hereford Conference, Queenstown - 17 confirmed cases, 2 probable
• Private wedding, Wellington - 10 confirmed cases, 2 probable
• Group travel to US, Wellington - 15 confirmed cases, 2 probable
• Rest home, Hamilton - 11 confirmed cases
• Matamata - 23 confirmed cases
• Workplace, Christchurch - 8 confirmed cases, 1 probable