Libya’s Petroleum Facilities Guard halted crude shipments from Zueitina port indefinitely amid an escalating conflict between the divided country’s rival governments, putting the OPEC member’s oil exports at risk, Bloomberg reported.

Zueitina will be closed until further notice, and tankers seeking to load crude there must register with the National Oil Corp. loyal to the internationally recognized government in eastern Libya, according to a Petroleum Guard spokesman Ali al-Hasy.

Vessels registered with a rival NOC administration in Tripoli, seat of an Islamist-backed government in western Libya, are “illegitimate” and won’t be permitted to load at the eastern port, he said.

The Tripoli-based NOC, which has been in charge at Zueitina, declared force majeure and said in a statement that the port was closed for all exports due to a “deteriorated security situation”. Force majeure is a legal status protecting a party from liability if it can’t fulfill a contract for reasons beyond its control.

Zueitina resumed loadings on October 5th, boosting the country’s export capacity after a five-month halt due to protests, a port-workers union said at the time.

Zueitina had only recently reopened, helping the OPEC member country boost crude oil exports to around 450,000 bpd last month from closer to 350,000 bpd earlier this year.