TRIPOLI - Head of the UN Support Mission in Libya (UNSMIL) announced Tuesday that the parties of the conflict in the eastern Libyan city of Benghazi agreed to a 12-hour humanitarian truce.

"The different parties to the conflict in Benghazi have agreed to an unconditional humanitarian truce in the affected areas, which commenced at 7 am local time today, Nov 19, 2014, for a period of 12 hours, and is subject to extension by the parties," Bernardino Leon said in a statement.

"As agreed with all parties, the Libyan Red Crescent will evacuate civilians, retrieve the bodies and facilitate the removal of sewage from the affected areas," the statement added.

The mission stressed that this truce will give "civilians the opportunity to attend to the injured and restock food and other necessary supplies."

The UNSMIL urged all parties to fully comply with their obligations during this truce.

However, some local witnesses told Xinhua that "sound of heavy weapons and explosion could be heard in southeastern Benghazi, in the areas of Al-Laithi and Boatni and on the road leading to the Benghazi airport."

"According to eyewitnesses, an unmanned aircraft flew over the Al-Sabri area and was targeted by ground missiles, but it did not respond to the firing. Al-Sabri is experiencing a fragile truce," according to one of the witnesses.

Witnesses said heavy clashes took place in different parts of the city, including the southwestern and western areas, between the army and Islamist militants.

Since Oct 15, the Libyan army and forces loyal to the retired Major General Khalifa Haftar are waging a war to restore the city of Benghazi which had been held by Islamist militias.

Benghazi, the birthplace of the 2011 protests that toppled Libya's Muammar Gaddafi, has witnessed a drastic escalation of violence since then. The city is now plagued by assassinations, kidnappings and deadly clashes between different armed groups.