Israeli troops were reportedly fighting Hezbollah militants in two locations near the border.
The IDF said it carried out an airstrike on three Hezbollah training camps and on Hezbollah-run Al Manar television in eastern Lebanon on Thursday.
In the hours that followed, Katyusha rockets fired by Hezbollah militants rained on cities in northern Israel, including in and around Tiberias, as well as Karmiel, in the east, the IDF said.
There were no reports of injuries.
In southern Beirut, CNN’s Nic Robertson described hearing a “huge” blast shortly after daybreak Thursday. Lebanese TV showed a large plume of smoke over the city skyline.
It was not immediately clear what had been targeted or hit.
On Wednesday, Israeli warplanes dropped 23 tons of bombs on a bunker where Hezbollah leaders were holed up, according to the IDF.
Hezbollah said via its Al-Manar television station that none of its leaders was in the bunker at the time of the huge Israeli airstrike. Hezbollah earlier said Israel hit a religious center with the attack.
Dozens of bombs landed at about 11:30 p.m. (4:30 p.m. ET), the IDF said. CNN crews in Beirut said they didn’t hear any explosions or the sound of jets at the time the strike is said to have occurred.
The conflict so far has caused “immeasurable loss” in Lebanon, Prime Minister Fouad Siniora said Wednesday. He again called for a cease-fire and denounced Israel as a “savage war machine” responsible for more than 300 deaths in Lebanon.
Another 1,000 people have been wounded and 500,000 displaced since hostilities began a week ago, Siniora said in a televised national address.
The Lebanese Internal Security Forces reported, however, that 216 people had been killed and 524 injured as of 8 p.m. (1 p.m. ET) Wednesday.
Siniora’s call for a comprehensive cease-fire came as Israel’s military continued its battle — by air and by ground — against Hezbollah targets inside Lebanon.
Two Israeli soldiers died in heavy fighting, while Hezbollah rockets killed two Israeli children in northern cities, the IDF said.
CNN’s Karl Penhaul reported seeing many civilian casualties at the main hospital in Tyre, Lebanon, about 15 miles (24 kilometers) from the Israeli border.
In its ongoing air assault, Israel’s military targeted Beirut, hitting a vehicle in the city’s Christian neighborhood — shocking residents who do not wholly support the Islamic militant group.
Israel has rejected calls for a cease-fire until it can push Hezbollah back from its northern frontier and retrieve two soldiers kidnapped in a cross-border raid July 12.
Hezbollah continued to fire rockets into northern Israel on Wednesday, killing two children in Nazareth, the southernmost point where Israeli casualties have been reported so far. With Wednesday’s deaths, 29 Israelis — 15 civilians and 14 soldiers — have been killed in the weeklong fighting, according to the IDF.
The Israeli cities of Haifa, Tiberias, Acre, Shlomi and Carmiel were also targeted Wednesday.
Most residents are staying in bomb shelters or have left.
The IDF confirmed its ground troops launched what it described as a pinpoint operation inside southern Lebanon. But the IDF did not say where the operation took place.
“Their mission is to destroy Hezbollah outposts,” an IDF spokesman told CNN early Wednesday.