At least three people were killed after a 7.0-magnitude earthquake shook a remote region of northwestern Papua New Guinea before dawn Monday.
The country's National Disaster Centre said dozens of homes were also affected as emergency crews continued to assess the damage across difficult terrain.
The quake struck at a depth of 62 kilometres (38 miles) near the Chambri Lake system in the sparsely populated region of East Sepik Province, the US Geological Survey said.
"Chambri lake is boiling and the continuous quake is still happening right now," a member of parliament in the area, Johnson Wapunai, said in a message on social media several hours after the quake struck.
The lawmaker urged people to watch out for falling objects or trees, and to be on alert for further seismic activity.
No tsunami warning was issued.
Colles Pinga, who lives not far from the epicentre, told Australia's national broadcaster that three homes in his village were destroyed and people have been injured.
"There's landslides along the riverbanks... it's quite frightening," Pinga told the Australian Broadcasting Corporation.
The quake also left cracks on the interior floors of a new regional hospital that was nearing completion about 60 kilometres away, and also unlodged the building's paving stones, according to photographs taken by a doctor at the scene.
Loosening of soft ground in the quake zone can cause substantial subsidence and horizontal sliding of the ground and result in major damage, the USGS said.
The earthquake shook an area about 100 kilometres east of the border with Indonesia on the island of New Guinea.
The remote New Britain region, part of an archipelago in eastern Papua New Guinea, was struck by a magnitude 6.2 earthquake in late February.