Tunisian protesters threatening to blockade gas production in the south of the country on Thursday rejected a government offer of jobs and investment and moved their protest closer to a pipeline and pumping station.

The protests in southern Tatatouine are testing Prime Minister Youssef Chahed's government and have already forced two foreign energy companies to halt production or remove staff as a precaution because of threats of disruption.

Six years after Tunisia's revolution ended Zine El-Abidine Ben Ali's autocratic rule, the North African state is still struggling to deliver economic opportunities to unemployed youth in marginalised regions like Tatatouine.

Around 1,000 protesters have been camped out for weeks in the Sahara near a gas pipeline in a region where Italy's ENI and Austria's OMV have operations. But government attempts to broker a deal with job offers have so far failed.

"We will not accept the offers of the government because these jobs are not immediate. These unemployed youths can not wait," said Tarek Haddad, one of the protest leaders, in a video message on Facebook.

He said the protest would move to Vana, closer to a nearby pumping station, warning protesters would not retreat. Soldiers have recently moved into the area around the pumping station.

President Beji Caid Essebsi a week ago ordered the army into the area to protect strategic energy and phosphate production.

The government has already offered 1,500 jobs with energy companies, including 1,000 immediately and 500 next year. Officials have also offered 2,000 jobs in horticulture and environmental projects as well as $20 million to develop projects in the region.

"We want seriously to find solutions for the expectations of the protesters, but sometimes there are more demands than the possibilities," said Marbouk Korchid a senior official in the government said. "There are some exaggerated demands."

ENI says the protests have not affected production. But OMV has removed 700 non-essential staff as a precaution. Perenco halted production at its Targa and Baguel fields, while protests closed Canada-based Serinus Energy's Chouech Essaida field.

The protests are another challenge for Chahed whose government is struggling to push through sensitive subsidy and public spending reforms demanded by the IMF and other lenders to help stabilize economic growth.

Tunisia is a small oil and gas player with production at around 44,000 barrels per day, but its economy is just recovering from 2015 Islamist militant attacks on foreign visitors that hit the vital tourist industry hard.