The UN peacekeeping mission says it is “investigating the origin of the explosion” that hurt four of its personnel on a patrol mission in southern Lebanon, Al Jazeera reports.

This comes after security sources told Reuters that Israel was behind the strike near the border town of Rmeish, a claim Israel’s military has denied.

UNIFIL, in a statement, said the “safety and security of UN personnel must be granted” and called for an end to the near-daily cross-border attacks by Israel and Hezbollah.

“All actors have a responsibility under international humanitarian law to ensure protection to non-combatants, including peacekeepers, journalists, medical personnel, and civilians,” said the UNIFIL statement.

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