SYDNEY - Papua New Guinea Prime Minister James Marape on Wednesday blamed "extraordinary rainfall" and changes to weather patterns for multiple disasters in the Pacific Island nation this year, including a landslide last week which may have killed thousands.

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Parts of a mountain in the Maip-Mulitaka area in Enga province in PNG's north collapsed in the early hours of last Friday and Marape said more than 2,000 people are estimated to have died, with up to 70,000 people living in the area impacted by the disaster.

PNG on Wednesday ramped up rescue efforts, while authorities raised concerns about the outbreak of diseases amid warnings of further landslides. Thousands of people have been ordered to evacuate amid further earth slips in the mountain

"Our people in that village went to sleep for the last time, not knowing they would breathe their last breath as they were sleeping peacefully. Nature threw a disastrous landslip, submerged or covered the village," Marape told parliament on Wednesday.

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Natural disasters have cost the country more than 500 million kina ($126 million) this year, before the landslide at Enga, he said.

"This year, we had extraordinary rainfall that has caused flooding in river areas, sea level rise in coastal areas and landslips in a few areas," Marape said.

Defence Minister Billy Joseph was traveling to the scene of the landslip on Wednesday with relief supplies provided by Australia, the government said. Military personnel from Australia and New Zealand would help with the relief and reconstruction.

PNG on Wednesday ramped up rescue efforts, while authorities raised concerns about the outbreak of diseases amid warnings of further landslides. Thousands of people have been ordered to evacuate amid further earth slips in the mountain.

Residents have been using shovels and bare hands to dig through mud and debris almost two storeys high even as officials said chances of finding survivors were slim.

Slow rescue

Rescue teams have been slow to reach the site because of the treacherous terrain and tribal unrest in the remote area, forcing the military to escort convoys of relief teams.

The landslide had hit a section of highway near the Porgera gold mine, operated by Barrick Gold through Barrick Niugini Ltd, its joint venture with China's Zijin Mining. The miner said its operations were not affected.

Marape said the government was working with Barrick to reopen the road. Barrick said it had offered the government more heavy equipment at the slip site.

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The United Nations, in its latest update, said a bridge had collapsed on Tuesday on the main road toward the disaster area, potentially delaying rescue teams reaching the site.

The UN migration agency has warned of an outbreak of infectious diseases if immediate steps are not taken.

"Every passing minute, bodies buried under the debris are decaying, with water squeezed between the ground and the vast debris covering an area of three to four football fields is continuing to leak, this is posing a high health risk," Serhan Aktoprak, the chief of the agency's mission in Papua New Guinea said in an emailed statement.