UNITED NATIONS, June 4 (Xinhua) -- UN Secretary-General Antonio Guterres on Thursday condemned the killing of a UN peacekeeper in southern Lebanon and urged all parties to respect the cessation of hostilities agreement.

Sgt. Milovan Jovanovic, a Serbian peacekeeper serving with the UN Interim Force in Lebanon (UNIFIL), was killed on Wednesday when a mortar struck a UN position near Marjayoun in southern Lebanon, according to a statement by UN spokesperson Stephane Dujarric.

Two other peacekeepers were wounded in the incident and are receiving treatment at a UNIFIL medical facility. An investigation is underway, the statement said.

Seven UNIFIL peacekeepers have been killed since hostilities escalated in Lebanon on March 2 following the Israeli-U.S. war on Iran.

"Attacks on peacekeepers must stop. They are grave violations of international humanitarian law and of Security Council Resolution 1701 (2006) and may amount to war crimes," the statement said.

Guterres called on all parties to uphold their obligations under international law, ensure the safety and security of UN personnel, and respect the inviolability of UN property and assets. He also stressed that all attacks on peacekeepers must be promptly investigated and that those responsible must be held accountable.

The secretary-general reiterated his call for all parties to respect the cessation of hostilities between Israel and Lebanon announced on April 16. The United Nations remains committed to supporting diplomatic efforts to extend the truce and fully implement Resolution 1701, which was adopted to help end the 2006 war between Israel and Hezbollah, the statement said. ■