Two members of a United Nations peacekeeping mission stationed near Lebanon’s border with Israel were injured on Thursday when an Israeli tank fired at one of their observation towers, U.N. officials reported.

This marks the most serious incident involving the international peacekeeping force since Israel had previously warned them to relocate from positions in Lebanon, close to where Hezbollah fighters were launching rockets into northern Israel. The U.N. forces, however, declined to move, according to a spokesperson.

UNIFIL, the U.N. peacekeeping force, has been stationed in southern Lebanon since 1978, primarily for observation. Its mandate was extended in 2006 after the last major conflict between Israel and Hezbollah, an Iran-backed militant group.

Over the past year, the peacekeepers have increasingly found themselves in the midst of cross-border attacks. Following Hamas’s attack on Israel on October 7, Hezbollah also began firing rockets into Israel, to which Israel responded with military strikes. Just last week, Israeli forces entered Lebanon to confront militants.

Below is an overview of the growing challenges faced by the peacekeepers amid rising tensions at the border.

What is the role of UNIFIL?
The United Nations Interim Force in Lebanon (UNIFIL) comprises over 10,000 civilian and military personnel from 50 nations, tasked with preventing violations along the 75-mile border between Lebanon and Israel, commonly referred to as the Blue Line.

A U.N. resolution from 2006 grants the force authority to “ensure that its operational area is not used for hostile activities.” They are tasked with keeping weapons and fighters out of the region. However, over the past decade, both the U.S. and Israel have argued that the force has been largely ineffective in stopping Hezbollah from stockpiling and launching rockets from the territory they monitor.

Although UNIFIL’s peacekeepers are armed, their use of force is limited, typically reserved for situations where their own safety or the safety of civilians is under immediate threat. Their primary duty is to prevent border violations and report any incidents to the U.N. Security Council.

What’s happening now?
During Israel’s recent incursion into southern Lebanon, new Israeli military positions were established near one of UNIFIL’s bases, according to U.N. sources. Satellite images confirmed these new positions, and a U.N. spokesperson mentioned that Israeli forces were firing at Hezbollah positions from these new sites, putting the peacekeepers at increased risk. Israel had asked UNIFIL to relocate, but the request was refused.

Despite the fact that attacks on U.N. personnel violate international law, Hezbollah has been firing rockets into northern Israel from areas close to U.N. positions in southern Lebanon for the past year, complicating the peacekeepers’ mission.

On Thursday, UNIFIL reported that an Israeli tank shell hit one of their observation towers at the Naqoura headquarters in Lebanon. Soldiers also reportedly targeted the entrance of a bunker at a nearby base where peacekeepers were taking shelter.

In a statement, the U.N. force condemned the incident, calling any intentional attack on peacekeepers a “serious violation of international humanitarian law.” They stated they are in communication with the Israeli military for follow-up. Israel confirmed that its forces were operating near UNIFIL positions on Thursday morning and had instructed the U.N. forces in the area.ed fire in the area.”