The Serbian peacekeeper, who died from wounds sustained Wednesday from mortar fire at his base, is the seventh person from the UN peacekeeping force in Lebanon (UNIFIL) killed since Lebanon was drawn into the broader Middle East war in early March.

Two other peacekeepers were wounded in the shelling.

"The secretary-general again urges all actors to respect the cessation of hostilities announced on 16 April 2026," said Stephane Dujarric, the spokesman.

The violence in southern Lebanon has come amid attacks by Hezbollah against Israel in retaliation for the Israeli-American offensive against Iran in late February.

"All attacks on peacekeepers must be promptly investigated, and those responsible must be effectively prosecuted and held accountable," Dujarric said, noting that UNIFIL had launched its own investigation.

Based on preliminary observations, "we understand that the position was struck by indirect fire from north of the Litani River," he added.

The Israeli army accused Hezbollah of being behind the attack late Wednesday in Ibl al-Saqi.

Hezbollah chief Naim Qassem on Thursday demanded Israel's withdrawal from Lebanon, as an official from his group confirmed it rejected a truce announced following talks between the two countries in Washington.

Guterres on Monday said that peacekeepers would be needed in Lebanon after the UNIFIL's mandate expires at year-end -- an option likely to face opposition from the United States and Israel.