Argentina's state-run energy firm YPF said it started normalizing oil and natural gas production in part of energy-producing province Neuquen on Sept. 4 after output was paralyzed earlier in the week by indigenous people protesting land rights.

"A team of 34 technicians were able to enter the Loma La Lata field to check production installations, evaluate potential damage caused by the shutdown and normalize operations," YPF said in a statement.

Earlier on Sept. 4, YPF said 400 oil wells and 300 gas wells had been shut down in the Loma La Lata, Loma Campana and Rincon del Mangrullo fields, resulting in a production loss of 16 million cubic meters of gas and 32,000 barrels of crude.

Protesters from the indigenous Paynemil community had barricaded roads, cutting off access to the Vaca Muerta shale field as part of a demonstration over territorial claims.

YPF said it had begun legal action against the Paynemil community to ensure future access to Vaca Muerta wells.

The Paynemil claim ancestral rights to land in Neuquen province and their grievances could be a thorn in the side of future joint ventures between YPF and foreign firms. Argentina needs $200 million in new investments to exploit the vast Vaca Muerta shale fields.