Libyan authorities have clashed with striking oil workers and blocked attempts by strikers to sell oil themselves at the country's largest crude terminal.
The head of Libya's Petroleum Facilities Guard (PFG), Edris Abokhamada, said he had contacted the defence ministry for reinforcements after clashes on Tuesday at the Zueitina oil port, which has been shut since mid-July.
"The protesters are still inside the port but the citizens want them to leave," Abokhamada told the Reuters news agency. "The Zueitina port protesters fired on civilians when they asked them to leave. One is injured."
Independent confirmation of the shooting was not immediately available.
Local resistance to strikes has shown the stranglehold on Libya's vital oil exports loosening, industry sources in the country say. A second oil port, Marsa al-Brega, reopened on Tuesday.
Abokhamada said that the protesters at Zueitina were allied with Ibrahim al-Jathran, the leader of strikers at the biggest oil port, Es Sider, who before his dismissal was PFG leader in central Libya.
The government has said workers have demanded higher pay and want to export oil independently, although the protesters have not voiced demands themselves.
The Zueitina port protesters fired on civilians when they asked them to leave. One is injured.
The Libyan port authority asked their customers to remove their tankers from the Es Sider terminal late on Monday, trading and shipping sources said, to prevent any potential illegal oil sales.
Port authorities also reportedly stopped an oil tanker from "illegally entering" the port on Tuesday.
One oil trading source said he had received emails offering Libyan oil outside of state National Oil Corp's control.
Striking security guards and other worker protests have blocked the main ports since July and led to the closure of many oilfields, cutting exports and production to their lowest levels, with exports less than 500,000 barrels per day, since the civil war in 2011. Before then export capacity was up to 1.25 million bpd.
Libya said last week it would use military force if necessary to prevent striking security guards from exporting oil independently.
The order for tankers to leave Es Sider is unusual, one trader said, and came after the state oil company declared force majeure on exports from four ports due to striking security guards.
"All vessels at Es Sider anchorage should sail urgently," the shipping source said.