BEIRUT — Israeli troops have captured a strategic mountain topped with a Crusader-built castle in southern Lebanon in the deepest incursion of the country in 26 years, the military said on Sunday.

The capture of Beaufort Castle, near the city of Nabatieh, came after days of airstrikes and intense fighting in nearby villages where Israeli troops fought Hezbollah militants in the rugged area.

Its capture marks a major development in the latest conflict, despite a ceasefire that has been in place since April 17.

The Israeli military's spokesman Avichay Adraee posted a photograph on X showing Israeli troops walking outside the castle, and Defense Minister Israel Katz wrote on X that they had raised an Israeli flag over the castle.

Israeli troops previously captured the castle in 1982 and held it until they withdrew from Lebanon in 2000.

The Beaufort fortress, perched high atop Lebanon's rolling green hills and overlooking the Litani River, has been a strategic military asset for many armies over almost 1,000 years.

Built as a Crusader castle around the 12th century on top of previous fortifications, it has been used by the Crusaders, Saladin's Jerusalem army, Mamluks, Ottomans, the French mandate, the Palestine Liberation Organization and the Israeli military until 2000, when it was partially restored and opened to visitors.

The Crusaders named it Beaufort, which is Old French for "beautiful fortress".

The Israeli military said in a statement that it launched an operation a few days ago in the Beaufort Ridge and the Suluki Valley farther south with the aim of dismantling Hezbollah infrastructure and removing direct threats to Israeli civilians.

Israeli Prime Minister Benjamin Netanyahu said in a videotaped statement on Sunday that he had instructed the military to deepen and expand its grip on Lebanese areas held by Hezbollah.

He described the seizure of the Beaufort as "a dramatic stage and a dramatic shift in the policy we are leading".

Agencies - Xinhua