The U.N. refugee agency said nearly 100,000 people have been displaced within Lebanon and tens of thousands of Syrian refugees there have fled back over the border.

They called the situation a “major humanitarian emergency”.

Israel has issued large-scale evacuation orders for southern Lebanon and parts of Beirut.

“UNHCR has declared the escalating crisis in the Middle East as a major humanitarian emergency requiring an immediate response across the region and into Southeast Asia,” Ayaki Ito, the U.N. refugee agency’s Director of Emergency and Programme Support, told a Geneva press briefing.

Ito said the figures given for the scale of displacement so far are likely an underestimate.

He also said that some 100,000 people have been displaced within Iran in the first days of the conflict and that UNHCR staff there are receiving hundreds of calls daily from Iranians seeking assistance.