Escalating attacks by militant group Hezbollah risk "dragging Lebanon into a war", Israel's military said Sunday, after renewed cross-border exchanges of fire that have raised fears of a wider conflict.

"Hezbollah... is dragging Lebanon into a war that it will gain nothing from, but stands to lose a lot," warned Israel Defense Forces spokesman Jonathan Conricus.

The Lebanese group is allied with Hamas, which touched off the latest violence with a murderous October 7 rampage in Israel that killed at least 1,400 people, mostly civilians who were shot, mutilated or burnt to death, according to Israeli officials, reports AFP.

Israel has retaliated with relentless strikes on Gaza that have killed more than 4,300 Palestinians, mainly civilians, according to the Hamas-run health ministry.

It has also exchanged fire with Hezbollah across its northern border, with Conricus accusing the group of a dangerous escalation.

"Hezbollah is playing a very, very dangerous game. They're escalating the situation. We see more and more attacks every day," he said.

"Is the Lebanese state really willing to jeopardise what is left of Lebanese prosperity and Lebanese sovereignty for the sake of terrorists in Gaza?" he asked.

"That's a question that the Lebanese authorities need to ask themselves and answer."

Recent exchanges of fire have killed four Hezbollah fighters and a member of Palestinian militant group Islamic Jihad in Lebanon, while three Israeli troops were injured, one seriously, in Hezbollah anti-tank fire, and two Thai farm workers also wounded.

Israel has ordered dozens of northern communities to evacuate, and several thousand Lebanese have also fled border regions for the southern city of Tyre.

Hezbollah number two Naim Qassem has warned the group could step up its involvement in the conflict.

"Let's be clear, as events unfold, if something comes up that calls for greater intervention by us, we will do so," he said.

Iranian-backed Hezbollah fought a devastating war with Israel in 2006 that left more than 1,200 dead in Lebanon, mostly civilians, and 160 dead in Israel, mostly soldiers.