Crude oil prices were up by more than 1% during early trading on Monday with the halt in output and exports from oil-rich Libya with the escalation of civil conflict.

The El Sharara oil terminal in Libya was seized over the weekend by groups loyal to Libyan warlord Khalifa Haftar, cutting it off from the country’s northwestern port of Zawiya — a key port for oil exports.

Libya’s National Oil Corporation (NOC) declared a force majeure on Saturday, and said the halting oil exports would result in the loss of crude oil production of 800,000 barrels per day (bpd)

Read more: Oil prices gain 1% with Libya shutdown