There are no mail deliveries in many parts of Hawke's Bay today as posties avoid going outside due to ash and haze caused by the Tongariro eruption.
New Zealand Post said there will be no deliveries by posties today in Napier, Hastings and Waipukurau.
Spokesperson Jaimee Burke said New Zealand Post had heeded Civil Defence advice for people to avoid being outdoors due to ash and haze caused by the eruption.
"We regret any inconvenience to customers but the safety and wellbeing of our Posties who are out on foot and bikes is a priority.
"We are keeping a close eye on conditions and will resume deliveries once conditions allow," Jaimee Burke said.
Meanwhile Civil Defence has advised communities in the ash fallout zone in Hawke's Bay to take urgent action to protect their drinking water from contamination.
Notices have been dropped to residents on the Napier Taupo Road near Te Pohue and Te Haroto and also to communities on the Napier Taihape Road.
People who live in the ash zone are being advised to save water at an early stage as the supply could become contaminated.
Downpipes that lead to water tanks, gulley traps and gutters should be disconnected to prevent blockages and the ash should be allowed to empty onto the ground.
Disconnecting downpipes from the drinking water tank before rainfall will also help protect the water supply.
Civil Defence said gutters and roofs should be kept clear of ash buildup to prevent the possibility of collapse. When the ash has cleared, people are advised to hose off the roof before connecting pipes.
Residents have been advised to stay inside during periods of ash fall and use protective clothing if they go outside.
Anyone who suffers from a respiratory illness is advised to stay indoors during ash fall with windows and doors closed and to call emergency services in the event of any breathing difficulties.
Air New Zealand has cancelled all flights in and out of Hawke's Bay today.
There are currently no road closures due to the eruption.
And despite being located in the Central Plateau region at the base of Mt Ruapehu and Mt Tongariro, NZ Army personnel currently training in the Waiouru Military Training Area have not been affected by last night's sudden eruption, according to Major Pat Hibbs of the NZ Army's Training and Doctrine Command.
"We had a number of people training in the region, who were evacuated from the training area as a precautionary measure once the eruption occurred. However, we have since done a risk assessment of the area and accordingly those same personnel have been able to continue with their training as scheduled.
"There has been no sign of any ash in the Waiouru Military Training Area and as a result there is no risk to the health of any of our personnel," said Major Hibbs.