Three Libyan soldiers have been killed and four others wounded in a suicide car bombing on a road checkpoint west of the city of Benghazi, according to a military official.

The attack happened on Tuesday when an assailant drove an explosives-laden car into the checkpoint, located about 100km west of Benghazi on the road to Ajdabiya, the official, who declined to be named, told the AFP news agency.

There was no immediate claim of responsibility for the attack but government forces have been battling Islamist fighters for control of Benghazi for months.

The same checkpoint was targeted by a similar attack in October but the attacker's car exploded before reaching the checkpoint and there were no other casualties.

Libya has descended into chaos since the fall of Muammar Gaddafi in October 2011 after a NATO-backed revolt, with rival governments and fighters battling to control the oil-rich North African country.

Libya's internationally recognised government, which has lost control of much of the country, has pleaded for international help in combating the fighters.

Source: Agencies