Sporadic clashes were reported Wednesday between the militant Libya Dawn Forces and tribal forces loyal to the Libyan army southwest of the Libyan capital.
Libya Dawn Forces, that combine a number of hardline Islamist groups, are still controlling the southwestern parts of Tripoli, MENA news agency reported.
Libya has plunged into chaos three years after overthrowing Muammar Gaddafi with militants, who once helped overthrow Gaddafi, now forcing the government to protect itself in the eastern part of the country.
Khalifa Haftar, a retired general, is now leading an operation to drive the militants out of the country with the blessing of the Libyan parliament.
Haftar initially fought for Muammar Gaddafi, then against him. He fought alongside Islamist rebel groups in the uprising that toppled Gaddafi in 2011 before becoming their nemesis this year.
The Libyan army, reinforced by gunmen loyal to the retired Haftar, has been waging a street war against Islamist militants in Libya's Benghazi city since mid-October, in an attempt to regain control of the city which fell into the hands of Islamists last July.
Benghazi was the birthplace of the 2011 protests that toppled Libya's former leader Muammar Gaddafi. The city has witnessed a drastic escalation of violence and become a major extremist base in North Africa since the US ambassador to Libya was killed in 2012.
