Three people were killed by Israeli air strikes in southern Lebanon late on Saturday, authorities said, despite the ceasefire in force between Israel and Hezbollah.
The Iran-backed militia's leader Naim Qassem gave a televised speech in which he said Hezbollah's patience for the "continuing aggression" is running out.
"Do you imagine we will remain silent forever? No. Everything has its limits," he said.
The Lebanese Health Ministry said a drone strike on a car in the Kunin area killed one man and wounded another person.
The Israeli military countered by saying the strike "eliminated the terrorist Hassan Muhammad Hammoudi", accusing him of being responsible for anti-tank missile attacks on Israeli territory.
In a second statement later on Saturday, the Health Ministry said a strike on a motorcycle in Mahrouna, near Tyre, resulted in "two martyrs and wounded one person", with one of the dead a woman.
The Israeli military said that strike "eliminated the terrorist Abbas Al Hassan Wahbi", a Hezbollah intelligence official "involved in efforts to rebuild Hezbollah and weapons transfers".
Finding Hezbollah's tunnels in the mountains of south Lebanon
"These activities constitute a blatant violation of the understandings between Israel and Lebanon," the army said.
The attacks came a day after Lebanon blamed Israel for earlier strikes that killed a woman and wounded 25 others. Lebanon's state-run National News Agency reported that the woman was killed in an Israeli drone strike on an apartment in the city of Nabatieh.
But Israeli military spokesman Avichay Adraee said on social media that the army "did not target any civilian building", attributing the death to a Hezbollah rocket set off by an Israeli strike.
The Israelis said they had "identified rehabilitation attempts made by Hezbollah beforehand and struck terror infrastructure sites in the area". Mr Adraee said the building "was hit by a rocket that was inside the site and launched and exploded as a result".
Lebanon’s President Joseph Aoun on Friday accused Israel of repeatedly violating the US-brokered ceasefire, which required Israel to fully withdraw its troops from Lebanon.
Under the deal, Hezbollah was obligated to pull its fighters back north of the Litani River, which lies about 30km from the Israeli border, leaving the Lebanese army and UN peacekeepers in charge of the area.
However, Israel has repeatedly bombed southern Lebanon since the ceasefire came into effect last November, aimed at ending over a year of hostilities.
Hezbollah leader Mr Qassem said in his speech on Saturday that the "continuing aggression" by Israel "must not be allowed to continue".
"The state must exert pressure, and it must fulfil all of its duties," he said, insisting Hezbollah had held up its end of the ceasefire bargain.
Israel also continues to occupy five strategic positions on the border.
Hezbollah, severely weakened by last year's fighting, did not intervene in support of its patron Iran in Tehran's 12-day war with Israel this month.
