At least 67 people have died in the earthquake that rocked Papua New Guinea last week, while thousands were left homeless and without food and clean water, the Red Cross told AFP on Monday.
Strong aftershocks have further damaged roads and caused landslides, making it difficult for aid workers to reach the worst-hit communities.
"Around 143,000 people are affected and 17,000 people have been generally displaced because their homes are either fully or partially damaged and not in a condition to live in," the PNG country head of the International Federation of Red Cross and Red Crescent Societies Udaya Regmi told the news agency from the capital Port Moresby.
An earlier toll had put the number of fatalities at 31.
While the region has no major urban centres, around 670,000 people live within 100 kilometres of the epicentre, according to the Red Cross.
The magnitude 7.5 quake that struck on Feb. 26 was the biggest to strike the country's highlands in nearly a century. It triggered landslides, flattening buildings and closing oil and gas operations.
ExxonMobil Corp said production of liquefied natural gas (LNG) would be knocked out for about eight weeks.
Three aftershocks of magnitude greater than 5 shook the mountainous Southern Highlands, about 600 km northwest of Port Moresby early on Monday, the US Geological Survey said, including a shallow magnitude 6 quake.