Three United Nations military observers and a Lebanese interpreter have been injured while patrolling the southern Lebanese border after a shell exploded near them, officials said.

The military observers are part of the United Nations Truce Supervision Organisation, which supports the UN peacekeeping mission in southern Lebanon (Unifil).

The blast came as clashes between the Israeli military and Hezbollah militants escalated in recent weeks.

Both sides have been exchanging fire since the Israel-Hamas war in Gaza broke out, propelling concerns that the near-daily clashes along the border could escalate into a full-scale war.

Local Lebanese media said an Israeli drone strike targeted the observers in the southern village of Wadi Katmoun near the border town of Rmeich.

The Hezbollah-run television station Al-Manar said the drone strike wounded three officers from Australia, Chile, and Norway, as well as a Lebanese interpreter.

The Israeli military on social media platform X, formerly Twitter, said: “Contrary to the reports, the IDF did not strike a @UNIFIL vehicle in the area of Rmeish this morning.”

Unifil spokesperson Andrea Tenenti said they are “investigating the origin of the explosion”, adding:“The targeting of peacekeepers is unacceptable.

“We repeat our call for all actors to cease the current heavy exchanges of fire before more people are unnecessarily hurt.”

Lebanese caretaker Prime Minister Najib Mikat condemned the incident in a statement.

Unifil was created to oversee the withdrawal of Israeli troops from southern Lebanon after Israel’s 1978 invasion.

The UN expanded its mission following the 2006 war between Israel and Hezbollah, allowing peacekeepers to deploy along the Israeli border to help the Lebanese military extend its authority into the country’s south for the first time in decades.