At least three people have died and almost 100 houses collapsed in a magnitude-6.9 earthquake that shook an area in northern Papua New Guinea that was already flooded by recent torrential rain, according to local media on Monday.

According to the United States Geological Survey (USGS), which monitors seismic activity around the world, the earthquake occurred on Sunday at 06:22 local time (20:22 GMT Saturday) at a depth of 40 kilometers, about 38 kilometers northeast of the town of Ambunti in the province of East Sepik.

The earthquake caused homes to collapse into flooded rivers and claimed the lives of a woman and her daughter in the village of Jikinumbu, and another child in Sotmeri, both in East Sepik, the Papuan newspaper Post Courier reported on Monday.

It also said the earthquake caused the collapse of some 93 homes, as well as bridges and infrastructure essential in this country rich in resources, but with difficult terrain and with almost 40 percent percent of its 10.5 million population living in poverty.

Defense Minister Billy Joseph said in a statement Sunday night that he was waiting for provincial reports on the impact of the earthquake to decide how best to respond.

"We have serious adverse weather conditions; and all emergency services in our country should be on high alert," said the minister, warning of the dangers at sea and the possibility of landslides occurring in an area already devastated by torrential rains.

It is estimated that some 24 people have died in recent weeks due to flooding and landslides in several mountainous and coastal areas of Papua New Guinea, where overflowing rivers have displaced thousands of people and damaged crops and orchards, and contaminated water sources.

Papua New Guinea sits on the Pacific Ring of Fire, an area of great seismic and volcanic activity that is shaken each year by about 7,000 earthquakes, most of them moderate.