A ceasefire between Israel and the Iran-backed Lebanese group Hezbollah was supposed to have taken effect on April 17 but has never been observed. Both sides accuse each other of violating it and justify their attacks by the other camp's alleged breaches.

"Bombings fell very close to the ruins of Tyre," a UNESCO World Heritage site, Culture Minister Ghassan Salame said.

The medieval Beaufort castle overlooking Nabatieh was "directly hit... we know that several bombs fell on this fortress", he added.

"The intensification of the battles means that these sites are in serious danger."

Lebanon was drawn into the Middle East war in early March when Hezbollah launched rockets at Israel over the killing of Iran's supreme leader in US-Israeli attacks, prompting Israeli strikes and a ground invasion.

In recent days, Israel has issued repeated evacuation warnings to swathes of the southern coastal city of Tyre and carried out heavy strikes.

Early Thursday, Israel's military warned it would target a building in Tyre which it showed on an accompanying map as located very close to the city's archaeological area.

Around two hours after the warning, AFP footage showed a fireball followed by smoke as a strike hit the district.

The region around the Beaufort castle is "the epicentre of the battle being waged for the control of localities" close to it, in the Nabatieh region, Salame said.

On Wednesday, an AFP correspondent saw smoke rising near the castle after what appeared to be artillery fire.

Israeli forces used the castle, also known as Qalaat al-Chakif, as a base during their previous two-decade occupation of southern Lebanon that ended in 2000.

Further south, Salame said "the multi-religious and extremely precious site of Shamaa, 10 kilometres (six miles) from Tyre, was severely bombed and lost at least three of its four domes".

He added that his ministry's teams do not have access to most of the targeted sites due to the ongoing fighting between Israel and Hezbollah.

He asked UNESCO to "appoint a special commissioner" to assess the impact of the violence on the sites, and said he would request a "UNESCO commission of inquiry to visit the area" once the fighting was over.

He said Lebanon had placed signs at all UNESCO World Heritage sites, "but apparently the Israeli air force does not really respect this identification".

According to Salame, Lebanon has "placed 79 sites across the country under enhanced UNESCO protection", including Tyre and Beaufort castle, since the last war between Israel and Hezbollah, which ended with a ceasefire in 2024.

"Non-compliance with these clauses would constitute 'serious violations' of the 1954 Hague Convention and... potential grounds for prosecution," UNESCO said that year.