Troops commanded by Libyan military strongman Khalifa Haftar launched an assault on Tuesday to seize two of the country's key eastern oil terminals, a spokesman said.

"Ground, sea and air forces launched joint attacks to liberate Ras Lanuf from terrorist groups," Khalifa al-Abidi said after orders were issued early Tuesday for the offensive, which is also targeting the nearby Al-Sidra oil terminal.

Both sites were seized by a rival, Islamist-led force earlier this month.