At least 40 people are feared dead after a landslide struck two villages in mountainous central Papua New Guinea on Tuesday, reports say.
The landslide occurred near the town of Mendi, National Disaster Centre director Martin Mosi said.
Officials were heading to the area from where they will fly by helicopter to the disaster site, he added.
Prime Minister Peter O'Neill was also heading to the scene on Wednesday, a spokesman told AFP news agency.
At least 20 more people are believed missing at the site of the disaster, which is near an ExxonMobil liquefied natural gas project.
"The numbers are fluctuating and they need to be verified,'' said Mr Mosi.
An ExxonMobil spokeswoman told AFP that all staff had been accounted for and the company had stopped work in the area.
"It was a big landslide and it covered a big area where there used to be small hamlets, so we are expecting a number of deaths," Mr Mosi added.
'Covered two villages'
Local news media is reporting that this was one of the worst landslides in Papua New Guinea, with a main road in the area blocked. Disaster management teams are moving into the area to assess the extent of damage.
Witnesses said the landslide area was about a kilometre long and a few hundred metres wide, Australian media said.
The Australian High Commission said it had offered assistance to the Papua New Guinea government.
Speaking to Radio Australia, a local Member of Parliament, Francis Potape, said there could be more landslides in the area.
The disaster happened in the early morning hours and covered two villages as people slept, he added.
"There are people buried under the ground and a number of them are children," he said.