"Based on the preliminary quake parameters... hazardous tsunami waves are possible for coasts located within 1,000 km (620 miles) of the natural disaster epicenter", the center said.
However the PTWC added that based on available data there is no tsunami threat to Hawaii.More news: More deaths linked to crossbow mystery
Kokopo town has a rapidly grown population of more than 20,000.
Just weeks ago a 7.2 natural disaster knocked items off shelves in Port Moresby - far from the epicentre - and was felt as far away as Australia.
MCDEM initially said it was assessing the potential tsunami risk to New Zealand.More news: Thousands protest in Kashmir over rape of three-year-old
New Zealand is not at risk of any tsunami following a power natural disaster which hit Papua New Guinea earlier this morning.
A 7.5-magnitude quake hit the rugged highlands region in February 2018 that triggered landslides, burying homes and killing at least 125 people.More news: Beloved Actor And Comedian Tim Conway Has Died at 85-Years-Old
The Ministry of Civil Defence and Emergency Management told 1 NEWS the natural disaster was assessed by GNS Science as having no tsunami threat to New Zealand. That quake hit areas that are remote and undeveloped, and assessments about the scale of the damage and injuries were slow to filter out.
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