Lebanon's health minister said on Thursday more than 40 rescuers and firefighters were killed by Israeli fire in three days, with 97 killed overall since Hezbollah and Israel began clashing last October.

Firass Abiad told reporters that in three days 40 people "among those working in ambulances and fire trucks" were killed.

He said 97 "paramedics and firefighters" had been killed and 188 wounded since fighting began.

The toll includes rescuers in organisations affiliated with Hezbollah or other Lebanese parties.

Since the clashes began, 1,974 people have been killed by Israeli fire, including 127 children, he said, adding that more than 9,350 have been wounded.

After nearly a year of low-intensity cross-border fighting, Israel has shifted the focus of its operation from Gaza to Lebanon, where heavy bombing has forced hundreds of thousands to flee.

This week, Israel announced that its troops had started ground raids into parts of southern Lebanon, a stronghold of Hezbollah.

Meanwhile, Lebanon's state-run media said three Israeli air strikes hit Hezbollah's south Beirut stronghold on Thursday, the latest raids following a night of intense bombardment.

"Enemy aircraft launched three strikes on (Beirut's) southern suburbs," the official National News Agency (NNA) reported.

This week, Israel announced that its troops had started "ground raids" into parts of southern Lebanon, after days of heavy bombardment of areas across the country where the militant group holds sway. (AFP)