Tribesmen bombed Yemen’s main oil export pipeline on Saturday disrupting crude exports and increasing concerns about oil operations as security continues to deteriorate.

The attack took place in the al-Habab area of the central oil-producing province of Maarib, officials told Reuters.

The Maarib Pipeline has a capacity of 200,000 barrels a day (b/d) and connects the Maarib oil field to the Ras Isa floating export facility in the Red Sea.

It has been regularly targeted by attacks since 2011, when long-serving President Ali Abdullah Saleh was forced to step down, and was most recently repaired in May. Tribesmen use the threat of attacks to push for jobs and other benefits from the government.

The latest disruption to the pipeline comes as the country struggles amid worsening fighting between Shia rebels and the government.