Two other peacekeepers also sustained injuries in the incident and are receiving medical treatment at a UNIFIL facility.

The force said that an investigation is underway “to ascertain the exact circumstances that led to this tragic incident…The violence must end.”

It is not clear where the shelling originated, but the development comes amid intensifying exchanges of fire between the Israeli military in southern Lebanon and Hezbollah fighters who are not part of Lebanese army.

“Deliberate attacks on peacekeepers are grave violations of international humanitarian law and of Security Council Resolution 1701, and may amount to war crimes,” UNIFIL stressed.

The attack came hours ahead of a US-announced ceasefire renewal agreement between Lebanon and Israel on Wednesday.

Highest price

The Serbian authorities have confirmed that the peacekeeper was a Serbian national who had received emergency medical care after his base came under attack. He was then helicoptered to a Beirut hospital where he died.

A total of seven UN peacekeepers have been killed in Lebanon since hostilities began on 2 March.

“We extend our deepest condolences to the family, friends, and colleagues of the peacekeeper who lost his life in the service of peace,” UNIFIL said in a statement. “Our thoughts also go out for the full and speedy recovery of the injured peacekeepers.”

In its announcement UNIFIL highlighted “an increasingly high number of trajectories and impacts” across south Lebanon.

The violence erupted on 2 March when Hezbollah fighters fired into northern Israel, shortly after Israeli-US bombing of Iran began at the end of February.

The latest truce deal which does not include Hezbollah reportedly involves the creation of “pilot zones” where Lebanon’s army will take control.

Living in fear

To date, the violence has uprooted more than one million people in Lebanon and left communities living in fear.

The UN Children’s Fund (UNICEF) has described how families in southern Beirut have been too afraid to stay in their homes, fearing attack.

“Most of them are coming during the day[time], checking their homes and leaving at night,” UNICEF spokesperson Christophe Boulierac told UN News.

On Monday, videos showed thousands of vehicles queuing to leave the capital’s southern suburbs, following warnings of impending Israeli strikes against Hezbollah strongholds.

“In Beruit alone, an estimated 200,000 people were displaced from the southern suburbs following the evacuation order issued by the Israel Defense Forces on 1 June,” said Stéphane Dujarric, UN Spokesperson, in an update on Wednesday.