Operations were suspended at Yemen's only gas export terminal Tuesday after armed tribesmen drove out soldiers guarding the site, accusing them of links to rebel forces.
The tribesmen pledged not to interfere in operations at the Balhaf plant, operated by Yemen LNG, in which France's Total has a stake of almost 40 percent.
"We have taken control of the security side... and positioned members of the tribes in points evacuated by the army," local tribal chief Nasser Bahaj told AFP from Balhaf.
"On the administrative side, employees are still there and we do not interfere in their business," he said.
Yemen LNG said Tuesday it had stopped operations at the Gulf of Aden terminal in the southern province of Shabwa due to a "force majeure".
Total stressed that security at the site had been maintained.
"Yemen LNG informs us that no intrusion has been made through the perimeter of the factory," it said in a statement.
Southern tribes have taken up arms against rebels that have advanced from the north in their fight against forces loyal to President Abedrabbo Mansour Hadi, who has fled to Saudi Arabia.
Bahaj said the tribesmen "have no problems with the company" operating the Balhaf terminal.
"Our problem is with the troops and the security unit that are allied with the Huthis and former president Ali Abdullah Saleh," he said.
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Yemen has descended deeper into chaos since a Saudi-led military coalition launched an air war on the Huthis and allied rebel troops on March 26.
Shabwa province has seen heavy clashes between southern fighters and rebel forces.
Yemen LNG said in a statement that due to "further degradation of the security situation in the vicinity of Balhaf" it has decided to stop production and export operations and start evacuating personnel.
It said the plant "will remain in a preservation mode" adding that it has "declared force majeure to its various stakeholders".
US-based Hunt Oil Company holds more than 17 percent in Yemen LNG, while South Korea's SK Corporation holds 9.55 percent, KOGAS six percent and Hyundai 5.88 percent.
A Total spokeswoman in Paris said earlier that there were no expatriate workers left on Yemen LNG sites.
The Balhaf terminal has an annual capacity of 6.7 million metric tonnes.
A tribal source said soldiers guarding the site were allowed to leave after they handed over their weapons.
The tribes "pledged to protect the installations against looting," the source said.
On Monday tribesmen overran the bases of two army brigades near the terminal.