Irish peacekeepers serving with the United Nations in Lebanon are now behind Israeli lines, according to military sources familiar with troop movements in the area.

Israel Defense Forces (IDF) has pushed so far into southern Lebanon they now occupy a large part of Ireland’s area of operations, which are monitored by Irish peacekeepers with the United Nations Interim Force in Lebanon (Unifil) mission, the sources said.

News that Irish peacekeeping bases and all Defence Forces troops are inside the area seized by Israel will raise concerns for their safety as the Iranian-backed militant group Hizbullah looks to target Israeli troops.

Although the main Irish base, Camp Shamrock, is now behind Israeli lines, no effort has been made to target the Irish or to take the lands where the camp is located.

A second Irish position – UNP 6/52 – is even deeper inside the area taken by the Israelis and is next to the disputed border, or the “blue line”, between Israel and southern Lebanon.

Unifil, which the Irish are serving with, said “an explosion inside a UN position near El Adeisse injured three peacekeepers, two seriously” on Friday.

That incident, which is under investigation, follows recent incidents in which three Indonesian soldiers, serving with Unifil, were killed. A Polish soldier, serving alongside the Irish, was injured in a roadside bomb attack.

A spokesman for the Defence Forces said all of the Irish troops were safe and accounted for, echoing a statement by Defence Forces Chief of Staff Lieut Gen Rossa Mulcahy.

In a video message on Thursday he assured families of the Irish troops they were “well and accounted for” in what was a “challenging operation environment”.

Camp Shamrock, Lebanon: A spokesman for the Defence Forces said all of the Irish troops in Lebanon were safe and accounted for. Photograph: Conor GallagherCamp Shamrock, Lebanon: A spokesman for the Defence Forces said all of the Irish troops in Lebanon were safe and accounted for. Photograph: Conor Gallagher

He said their safety was being closely monitored and communications with 127th Infantry Battalion on the ground were on a 24-hour basis.

Minister for Defence Helen McEntee said Ireland “remains steadfast in its commitment to peacekeeping and to supporting stability in Lebanon”. This was despite the recent killings of the Indonesian peacekeepers and the injury of others, in separate incidents.

However, she said these attacks underlined “the very real and growing dangers facing those serving with the United Nations in Lebanon”.

“The increased attacks on patrols and the broader escalation in hostilities are placing peacekeepers at unacceptable risk,” she said.

“Attacks on Unifil personnel are a clear violation of international law. Those who serve to maintain peace and stability must never be targeted and there must be full accountability for those responsible.”

Camp Shamrock, where more than 300 Irish troops are based, is beside the village of At-Tiri. While it has not been taken by the Israelis, they have advanced well north of it, including taking the village of Rchaf about 3km from Camp Shamrock.

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The IDF has advanced at least 10km inside southern Lebanon , giving rise to concerns, within the Defence Forces and the Government, that the Israelis are preparing to stay in the area.

Further IDF advances and live fire incidents look certain for the remainder of the time the Irish will serve with Unifil, which is winding down at year end.

Israel has been attacking southern Lebanon, and advancing into it, for a month, intent on driving out Hizbullah, with missile attacks in the region.

The 120km blue line had become a flashpoint for that conflict even before the IDF troops made significant advances into Lebanon.