Papua New Guinea soldiers have been deployed to the Highlands region where security problems are threatening two major resource projects.
A month ago, the O'Neill government issued a callout order for security forces in Hela region and Porgera in neighbouring Enga province.
Landowner disputes have disrupted key construction work in Hela's Hides area for the major liquified natural gas project, while Porgera's large gold mine has ongoing problems with illegal miners.
Mark Ekepa with the Porgera Landowners Association says the defence force operation has begun.
"They're sending up all these defence force plus police personnel up to Porgera and Hides. They came up on the 25th, 27th of this month. There were three Fokker 100 flights came up to Hagen and it looks like some will go to the LNG site and some will go to Porgera."