A World Health Organization (WHO) official warned on Tuesday of disease outbreaks in Lebanon due to crowded conditions in displacement shelters and hospital closures as medics have fled Israel's assault.

Israel's escalation of airstrikes across Lebanon since Sept. 23, followed by its ground offensive in southern Lebanon, has killed over 1,000 people in the past two weeks and triggered a mass flight.

"We are facing a situation where there is a much higher risk of disease outbreaks, such as acute watery diarrhea, hepatitis A, and a number of vaccine preventable diseases," the WHO's Ian Clarke, Deputy Incident Manager for Lebanon, told a Geneva press briefing by video link from Beirut.

The U.N. health agency has already warned that the system is overstretched and so far, five hospitals in the country have closed and four are only partly functional, Clarke said.

He added that hospitals had been shut because medics had either fled the fighting or been asked to evacuate by Lebanese authorities.

At the same briefing, a WHO official voiced concern about Lebanon's ability to feed itself, saying thousands of hectares of farmland across the country's south have burned or been abandoned amid the escalating attrition war.

"Agriculture-wise, food production-wise, [there is] extraordinary concern for Lebanon's ability to continue to feed itself," Matthew Hollingworth, WFP country director in Lebanon, said, adding that harvests will not occur, and that produce is rotting in fields.