"A peacekeeper was tragically killed last night when a projectile exploded in a UNIFIL position near Adchit al Qusayr," said a statement. "Another was critically injured."

The town of Adchit al Qusayr lies near Lebanon's southern border with Israel, where Israeli forces have been battling Hezbollah fighters for nearly a month.

Indonesia confirmed that one of its peacekeepers was killed and three others were wounded due to "indirect artillery fire".

The UNIFIL statement said they did not know the origin of the projectile but had launched an investigation.

"No one should ever lose their life serving the cause of peace," it added.

UN chief Antonio Guterres condemned the killing in a post on X. "This is just one of a number of recent incidents that have jeopardised the safety and security of peacekeepers," he said.

Lebanese state news agency NNA reported earlier that the position hit belonged to the Indonesian battalion serving with UNIFIL.

The war in the Middle East spread to Lebanon in early March after Iran-backed Hezbollah fired rockets at Israel.

Their attack came after the assassination of Iran's supreme leader Ali Khamenei on the first day of the US-Israeli offensive.

Israel has retaliated with wide-ranging air strikes on Lebanon, and Israeli forces are now advancing into numerous towns in southern Lebanon.

Israeli officials say they intend to set up a security zone extending 30 kilometres from the Israeli border to protect those living in northern Israel.

UNIFIL has reported that its positions have been hit more than once since the start of the latest fighting.

On March 7, three Ghanaian soldiers were wounded by gunfire in a border town in southern Lebanon.