Weeks of hostilities across the Lebanese-Israeli border have escalated, with growing casualties on both sides and a war of words fuelling concerns of a widening conflict between Israel and the Iran-backed Lebanese group Hezbollah.

Hezbollah has been trading fire with Israeli forces since its Palestinian ally Hamas went to war with Israel on Oct. 7.

Israeli strikes killed two people in south Lebanon on Monday, according to a first-responder organisation affiliated to the Hezbollah-allied Amal Movement.

On the Israeli side, a Hezbollah missile attack on Sunday wounded several workers from the Israel Electric Company and one died of his wounds on Monday, the firm said.

The exchanges mark the deadliest violence at the border since Israel and Hezbollah fought a month-long war in 2006.

So far, more than 70 Hezbollah members and 10 civilians have been killed in Lebanon, and 10 people including seven troops have been killed in Israel. Thousands more on both sides have fled shelling.

Escalating tension

Hezbollah leader Sayyed Hassan Nasrallah said on Saturday the Lebanon front would "remain active", and said there was "a quantitative improvement" in the pace of the group's operations.

Israeli Prime Minister Benjamin Netanyahu warned Hezbollah on Monday not to broaden its attacks.

"This is playing with fire. Fire will be answered with much stronger fire. They should not try us, because we have only shown a little of our strength," he said in a statement.

Asked at a news conference on Saturday about what Israel's red line was, Israeli Defence Minister Yoav Gallant said: "If you hear that we have attacked Beirut, you will understand that Nasrallah has crossed that line."

'Tit-for-tat'

Lebanon's caretaker Prime Minister Najib Mikati, in an interview with Al Jazeera on Sunday, said he was reassured by the "rationalism" of Hezbollah so far.

"We are preserving self-restraint, and it's up to Israel to stop its ongoing provocations in south Lebanon," he said.

US Defense Secretary Lloyd Austin characterised the violence as "tit-for-tat exchanges between Lebanese Hezbollah and Israeli forces in the north", predicting Israel would remain focused on the threat from Hezbollah "for the foreseeable future".

"And certainly no one wants to see another conflict break out in the north on Israel's border in earnest," he told reporters in Seoul, although he said it was hard to predict what might happen.