The United Nations peacekeeping force in southern Lebanon confirms that its headquarters in Naqoura was hit by explosions for the second time in 48 hours, a day after Israeli forces struck the same position.

Two peacekeepers from the UN Interim Force in Lebanon (UNIFIL) were injured after two explosions occurred close to an observation tower, the UN mission said in a statement on Friday.

“This is a serious development, and UNIFIL reiterates that the safety and security of UN personnel and property must be guaranteed and that the inviolability of UN premises must be respected at all times,” it added.

“Any deliberate attack on peacekeepers is a grave violation of international humanitarian law.”

One of the injured peacekeepers was taken to a hospital in the nearby city of Tyre, while the other was treated at the site.

The organisation also said “several T-walls at our UN position 1-31, near the Blue Line in Labbouneh, fell when an [Israeli military] caterpillar hit the perimeter and [Israeli] tanks moved in the proximity of the UN position”, referring to the demarcation line between Israel and Lebanon.

“Our peacekeepers remained at the location”, it said, adding that additional peacekeepers were sent to reinforce the position.

The Israeli military said in a statement it is conducting a thorough review of the incident where two peacekeepers were “inadvertently” hurt in southern Lebanon. It later said two personnel with the UN peacekeeping mission were wounded when Israeli forces responded to a threat.

It said it had instructed UNIFIL personnel to go to protected areas and remain there hours before the incident.

Lebanon’s Ministry of Foreign Affairs earlier said the attacks were on watchtowers and the main UNIFIL base in Naqoura and on the Sri Lankan battalion’s base.

Lebanon’s official National News Agency reported that artillery shelling from an Israeli Merkava tank wounded members of the Sri Lankan battalion, without specifying their exact location.

Speaking at a news conference in Beirut, Lebanese caretaker Prime Minister Najib Mikati said Israel’s actions were a “denounced crime”. He added that he had discussed efforts to reach a ceasefire in Lebanon with United States Secretary of State Antony Blinken.

Hezbollah also condemned the Israeli attacks. The group’s media chief Mohammad Afif said the attacks are targeting UN peacekeepers, civilians, residential areas, hospitals and medical staff, and slammed the “excuses” and justifications the Israeli military uses to keep hitting them, including saying they contain weapons and explosives.

UN Secretary-General Antonio Guterres on Friday said it was “very clear that this incident is intolerable and cannot be repeated”.

Russia’s Ministry of Foreign Affairs on Friday said it was “outraged” by the targeting of UNIFIL peacekeepers and demanded that Israel refrain from any “hostile actions” against them.

Human Rights Watch called for a UN inquiry into the attacks and said the deliberate targeting of UN missions is a “war crime”.

“UN peacekeepers in south Lebanon have long played a critical civilian protection and humanitarian role,” said Lama Fakih, Middle East and North Africa director at the New York-based rights group. “Any targeting of UN peacekeepers by Israeli forces violates the laws of war and dangerously interferes with UNIFIL’s civilian protection and aid work.”

China expressed “grave concern and strong condemnation” of Israel’s attacks on UN peace operations, as did India over the “deteriorating security situation along the Blue Line”.

India’s Ministry of External Affairs said: “Inviolability of UN premises must be respected by all and appropriate measures taken to ensure the safety of UN peacekeepers and the sanctity of their mandate.”

France summoned Israel’s ambassador to seek an explanation, the foreign ministry said in a statement.

“These attacks constitute serious violations of international law and must stop immediately,” the ministry said.

France has about 700 troops as part of the UNIFIL mission. None of its troops has been wounded so far. The ministry said that all sides in the conflict had an obligation to protect peacekeepers.

Assault on Blue Helmets

Friday’s incident comes a day after UN peacekeepers said the Israeli military “repeatedly” fired at UNIFIL headquarters and positions in southern Lebanon.

Two Indonesian peacekeepers were injured on Thursday and remained in hospital, the mission said.

UNIFIL personnel wear blue helmets to be clearly identifiable and their position is known to the Israeli military.

Israel acknowledged its forces had opened fire in the area, saying the Hezbollah fighters on whom it is waging war operate near UN posts.

The attack on Thursday prompted global condemnation.

Italian Defence Minister Guido Crosetto denounced the incident as a possible war crime, in a break from his country’s support for Israel throughout its yearlong war in Gaza and Lebanon.

“This was not a mistake and not an accident,” Crosetto told a news conference. “It could constitute a war crime and represented a very serious violation of international humanitarian law.”

UNIFIL spokesman Andrea Tenenti told Al Jazeera the attack was a “very serious” development.

He explained that Israel had previously asked the peacekeepers to move from “certain positions” near the border, but “we decided to stay because it’s important for the UN flag to fly in [the] south of Lebanon.

“At the moment, we are staying, we are trying to do whatever we can to monitor [and] to provide assistance,” Tenenti added.

Indonesian Foreign Minister Retno Marsudi confirmed the country’s peacekeepers were in hospital for further observation.

“Indonesia strongly condemns the attack,” she said. “Attacking UN personnel and property is a major violation of international humanitarian law.”