BENGHAZI, Libya (Reuters) - A jet from Khalifa Haftar’s east Libyan military forces intercepted a civilian plane on Sunday as part of its push to control the oil-rich south of the riven nation, the faction said.

Libya has been in turmoil since the NATO-backed toppling of Muammar Gaddafi in 2011, with parallel administrations and armed groups carving the nation into swathes of control.

Haftar’s Libyan National Army (LNA) began an offensive in the south last month to fight militants and take control of oil installations, and this week banned flights without its permission.

In a statement, the LNA said it scrambled a jet after a plane took off from the El Feel oilfield without permission, and forced it to land near Sabha, the largest town in south Libya.

It was allowed to continue to Tripoli, seat of the internationally-recognised government, after inspection.

The Tripoli government protested against the interception, saying the Libyan Airlines plane was carrying oil workers.

The LNA, which is allied to a parallel government in the eastern city of Benghazi, wants to secure the El Sharara oilfield, Libya’s largest, and occupied a pumping station 20km (12 miles) away on Wednesday, according to a field engineer.

The Tripoli government, striving to reassert its former control of El Sharara, has sent troops there, a source from the administration said.

El Sharara has been shut since December when local tribesmen and state guards seized it.