Lebanon will file a complaint against Israel at the UN Security Council over the construction of a concrete wall described as a new "act of aggression" within Lebanese borders.

The office of Lebanese President Joseph Aoun said an “urgent complaint” would be sent by Foreign Minister Youssef Rajji. It will include evidence from the UN that the wall has made more than 4,000 square metres of Lebanese territory inaccessible to the local population, it said.

Construction of the wall, encroaching on the Lebanese side of the UN-demarcated Blue Line, has provoked anger in a country where Israel already carries out regular air strikes. Independent MP Marc Daou denounced “an act of aggression against Lebanon, its sovereignty and its land”.

The complaint to the UN “is necessary”, as well as increased action by UN peacekeepers, he said. “The signal here is clear: the Israeli aggression continues, and there is no serious intent to stabilise the situation or to co-operate with the Lebanese government to resolve the current conflict.”

Israeli wall in southern Lebanon - in pictures

Workers construct the concrete wall. Reuters A watchtower near the wall. Reuters A view from Israel of the border separating northern Israel and southern Lebanon. AFP A United Nations Interim Force in Lebanon vehicle on patrol on the Lebanese side of the border. AFP Israeli workers lay concrete while working on the border wall. AFP Work continues on the wall. Reuters

A Hezbollah source condemned the move as an “Israeli escalation” and a “de facto annexation of Lebanese territory”. They said it “confirms Israel’s ambitions and its intention to continue its occupation and avoid committing to any agreement,” the source said.

The land grab, the source added, gives Hezbollah further legitimacy in its argument for refusing to surrender its weapons in the current situation – as the Lebanese government proceeds with a US-backed plan to disarm it.