Landowner groups have blocked a main road and vandalised equipment belonging to ExxonMobil's LNG gas project in Papua New Guinea's Hela province.
Police say landowners frustrated at continued delays in payment by the government of project royalties were behind the attack at the Angore well heads.
They set fire to and damaged earthmoving equipment, and have dug up a main road, hindering access to the project.
A spokesperson for ExxonMobil said the company was investigating the vandalism at Angore and monitoring ongoing tension in the Highlands
"We are investigating reports of vandalism relating to the Angore pipeline construction project. Host government security forces are in the area and also investigating," the spokesperson said.
She said LNG Project staff are all safe, and that production at the Hides Gas Conditioning Plant is continuing normally.
The police commander in Hela's capital Tari, Thomas Levongo, said the landowners' frustrations had been mainly directed at the government.
"They're complaining against the government delaying their payments, outstanding payments. That has been taking a long time," he explained.
"So people are not happy with the government, so they're going to disturb the government. That's what people are trying to do now."
Thomas Levongo also said reports from Hela's Komo district indicated that the large airfield there, which is used by the project, has been blockaded as well by landowners.
Police say the landowner actions were unrelated to unrest in neighbouring Southern Highlands where a state of emergency was declared last week.
The declaration followed a rampage by supporters of a losing election candidate who destroyed a commercial aircraft, set fire to the local courthouse, the provincial governor's house and other buildings in Mendi.
PNG's acting police commissioner Jim Andrews has announced a series of changes in the constabulary's regional command.
As well as various transferrals of Highlands commanders, Joseph Tondop has had his appointment as Southern highlands provincial police commander revoked.
The Mendi Police Station Commander, Chief Inspector Gideon Kauke is now the acting provincial police commander.
The police commission said two units of mobile police were on standby, ready to deploy to Mendi.
Two mobile police squads of nearly 70 personnel are in the area already, alongside dozens of Defence Force soldiers.
Meanwhile, acording to Mr Andrews, two warehouses in Mendi were also broken into during last week's unrest, and tonnes of relief supplies stolen, posing serious concerns for the welfare of people affected by the magnitude 7.5 earthquake in February in Hela province.