At least one company began evacuating non-essential personnel after a powerful 7.5 magnitude earthquake hit Papua New Guinea's energy-rich interior, causing landslides, damaging buildings and closing oil and gas operations.
The tremor on Monday hit in the rugged, heavily forested Southern Highlands about 560 km northwest of the capital, Port Moresby according to the US Geological Survey (USGS).
A spokesman at Papua New Guinea's National Disaster Centre said by telephone the affected area was very remote and the agency could not properly assess damage until communication was re-established.
He said there were no confirmed casualties, although the International Red Cross (IRC) in Papua New Guinea said some reports indicated there were "fears of human casualties".
The PNG government also said it had sent disaster assessment teams and defence force. At least 13 aftershocks with a magnitude of 5.0 or more rattled the area throughout the day, according to USGS data, but no tsunami warnings were issued.
Early on Tuesday, USGS reported that another quake with a magnitude of 6.4 had hit 142 km from the city of Mount Hagen at a depth of about 10 km.
ExxonMobil said it had shut its Hides gas conditioning plant and that it believed administration buildings, living quarters and a mess hall had been damaged. It also said it had suspended flights into the nearby Komo airfield until the runway could be surveyed.
Gas is processed at Hides and transported along a 700 km line that feeds a liquefied natural gas plant near Port Moresby for shipping.
PNG oil and gas explorer Oil Search said in a statement it had also shut production in the quake-affected area.
The giant Grasberg copper mine operated by the Indonesian unit of Freeport McMoRan in neighbouring Papua province was not affected, a Jakarta-based spokesman said.
