Israeli strikes force tens of thousands to flee southern Lebanon: UN

Tens of thousands of people have fled their homes in Lebanon as Israeli strikes battered the country, the UN has said, calling events "extremely alarming".

"We are gravely concerned about the serious escalation in the attacks that we saw yesterday," UN refugee agency spokesperson Matthew Saltmarsh told reporters Tuesday in Geneva.

"Tens of thousands of people were forced from their homes yesterday and overnight, and the numbers continue to grow," he said.

Some 100,000 people living near the border with Israel had already been displaced since October last year.

Israeli air strikes killed at least 558 people since early Monday, including 50 children and 94 women, according to Lebanon's Health Ministry.

At least four healthcare workers were killed and 16 paramedics injured, the World Health Organization said.

Monday's bombardment of Lebanon was by far the largest since the Lebanese civil war.

Several UN agencies said they were ramping up their aid in Lebanon to address a situation that was already dire before the escalation.

'Toll on civilians is unacceptable'

"This is a region that has already been devastated by war and a country that knows suffering all too well," Saltmarsh said.

He pointed out that even before the air strikes, there had been significant displacement from southern Lebanon.

"The situation is extremely alarming. It is very chaotic," he said.

"The toll on civilians is unacceptable."

Some 500 people have crossed from Lebanon to war-torn Syria, a Syrian security official told AFP Tuesday, fleeing the deadliest Israeli bombardment since Hezbollah and Israel fought a devastating war in 2006.

"Around 500 people crossed the border through the Qusayr and Dabousiya crossings between 1300 GMT and midnight" on Monday, the security official said, requesting anonymity to discuss sensitive matters.

"Vehicles were still crossing in the early hours of the morning, with people heading towards friends' and acquaintances' homes in the Homs countryside and the city of Homs," he said.

"The hospitals have been crazy challenged in managing the number of injuries since last week," WHO's representative in Lebanon, Abdinasir Abubakar, told reporters.

Speaking by video from Beirut, he said more than 90 percent of the wounds suffered last week when pagers used by Hezbollah exploded across Lebanon "are on the face and limbs, especially hands".