Eastern Libyan forces commander Khalifa Haftar urged his troops trying to take Tripoli to battle harder and teach their enemies a lesson, because the holy Muslim month of Ramadan that begins in Libya on Monday was a month of holy war.
His comments came just hours after the United Nations called for a week-long humanitarian truce following a month of fighting for the capital that has displaced 50,000 people.
Haftar's Libyan National Army (LNA) force, which is allied to a parallel government in the east, has not been able to breach the southern defenses of the Tripoli, which is held by the internationally recognized government.
On an audiotape released by his force's spokesman, Haftar said Ramadan had not been a reason to halt previous battles when he seized the eastern cities of Benghazi and Derna as he expanded his power and the country collapsed into chaos after the toppling of Moammar Gadhafi in 2011.
"Officers and soldiers in our armed forces and the auxiliary forces, I salute you in this glorious days and urge you with your strength and determination to teach the enemy a greater and bigger lesson than the previous ones, as we've always known you to do, till we uproot it from our beloved land," Haftar said.
In a statement earlier, the U.N. Mission in Libya (UNSMIL) appealed for a truce starting on Monday morning at 0400 local time to coincide with the beginning of Ramadan.
"UNSMIL calls on all parties to deliver of humanitarian aid to those in need and to ensure the freedom of movement for civilians during this truce," UNSMIL said in a statement.
Artillery shelling could be heard on Sunday coming from southern outskirts of the capital, where the LNA has been tying to breach defenses by Tripoli forces.
The LNA of Haftar - a former Gadhafi general - seized the sparsely populated but oil-rich south of the country earlier this year before turning on Tripoli last month.
The renewed conflict threatens to disrupt oil supplies, boost migration across the Mediterranean to Europe and scupper U.N. plans for an election to end rivalries between parallel administrations in east and west.