Relative calm prevailed Monday in Abu Grein, the contact line between Misrata brigades and ISIS militants, as Misrata brigades lack logistic support from the UN-proposed government.
The international community promised to provide support, including sophisticated weapons and ammunition, to eradicate ISIS from Sirte, but that has not happened so far.
The UN Security Council imposed an arms embargo on Libya in 2011.
Prime Minister of UN-proposed government Fayaz Sirraj, which mainly was formed to fight ISIS in Sirte, called for lifting embargo on arms sales to Libya that was imposed in 2011 by the UN Security Council.
"It doesn't make sense that the international community supports our war against terrorism, and forbids us from arming ourselves," he said at the Arab League in Cairo early this month.
Libya's Fatwa House has mourned the dead Misrata fighters in ISIS clashes and accused the Presidency Council of UN-proposed government of leaving the anti-ISIS fighters in Abu Grein without the needed weapons and ammunition.
"The Presidency Council has frozen the assets of state institutions, leaving the revolutionary fighters in Abu Grein without real support," The Fatwa House said in a statement.
Libya's UN envoy Ibrahim Dabbashi, who favors Dignity Operation, urged Sunday the Presidency Council not to arm what he called "the militias" that claim to fight ISIS, in an apparent reference to Misrata brigades.
"Sirte battle is not a militia war, it's a regular army's one. Attempting to prevent the army from liberating Sirte is kind of crazy," He tweeted.