GENEVA, March 6 (Reuters) - The U.N. refugee agency said on Friday that nearly 100,000 people have been displaced within Lebanon and tens of thousands of Syrian refugees there have fled back over the border, calling the situation in the region a "major humanitarian emergency".
Israel has issued large-scale evacuation orders for southern Lebanon and parts of Beirut amid hostilities with the Iran-backed Lebanese group Hezbollah since a U.S.-Israeli air campaign against Iran began on February 28.
"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 added that the figures given for the scale of displacement so far are likely an underestimate.
He 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.
The World Health Organization is stepping up disease surveillance in Lebanon due to the mass displacement, said regional director Hanan Balkhy.
"It worries us very much, the numbers of the displaced populations and the lack of adequate water and sanitation," she said.
(Reporting by Emma Farge, Editing by Friederike Heine and Miranda Murray)
