UN Secretary General Ban Ki-moon has called on the parties to an armed conflict in the Libyan city of Bani Walid to start peace talks, the UN reported on its website.

“The secretary general reminds all parties of their obligations under international humanitarian law and calls on all the Libyan authorities and those in Bani Walid to begin immediately a process to resolve the Bani Walid standoff peacefully,” the UN said.

Clashes between government forces and militant groups in Bani Walid, controlled by late Libyan leader Muammar Gaddafi’s supporters, began on Thursday. As a result, Gaddafi’s son Khamis was killed on Saturday.

“The secretary general believes that the situation in Bani Walid can be resolved in a peaceful manner that preserves the rights of all Libyan citizens and permits the state to exercise its responsibilities there,” the UN also said.

Gaddafi’s regime was overthrown in October 2011 by opposition forces with NATO’s assistance after a seven-month civil war. Gaddafi, who had ruled the country for almost 42 years, was captured and killed by rebels near his home town of Sirte on October 20.