The head of Libya’s Petroleum Facilities Guard, a force affiliated with the United Nations-backed government, called for a no-fly zone to protect critical oil installations, as fighting threatens to escalate in the holder of Africa’s largest crude reserves.

Idries Bu Khamada said he has asked the Presidency Council, led by Prime Minister Fayez al-Serraj, to approach allies about barring aircraft from flying over the Gulf of Sirte, home to Es Sider, Libya’s largest export terminal for oil, and Ras Lanuf, its biggest refinery. “They need international protection,” Bu Khamada said by phone.

The media office of Serraj’s council said eastern-based military commander Khalifa Haftar had been targeting the oil facilities since Sunday, including through airstrikes. Haftar’s forces were ousted from both Es Sider and Ras Lanuf this month, when the victorious militia handed control of the terminals to the oil guard. Since then, armed men from the east and west have been converging in the area.

Seven PFG members were killed on Monday and a technical workshop in Ras Lanuf was damaged by Haftar’s planes, according to the recently appointed Bu Khamada. If the international community doesn’t intervene, there’s a risk of damage to oil tanks, he said.

“Shelling and bombardment is intensive,” he said by phone late Monday. On Tuesday, Arabiya reported that Haftar’s Libyan National Army had launched an operation to regain control of Ras Lanuf. It wasn’t immediately possible to reach the LNA for comment.

More than a year after a UN-mediated peace deal meant to unite the nation and end years of conflict and economic ruin that followed the ousting of Muammar Qaddafi, Libya remains deeply divided. Killings, kidnapping and smuggling are common in a country awash with guns.