Al-Manar reporter Ali Shaib and reporter Fatima Ftouni, from broadcaster al-Mayadeen, were killed when their vehicle was hit.
Lebanon's information minister later said Ftouni's brother, cameraman Mohammed Ftouni, had also been killed in the strike.
Al-Manar is controlled by the Lebanese group Hezbollah and al-Mayadeen is widely seen as editorially aligned with Iran's allies and supporters in the region.
The Israeli military said in a statement it had "eliminated" Shaib, whom it described as a "terrorist" in a Hezbollah intelligence unit who had reported on the locations of Israeli soldiers in southern Lebanon.
It accused him of "incitement" against Israeli soldiers and civilians.
The military's statement made no mention of any other deaths and provided no evidence to support the assertion that Shaib was a member of Hezbollah.
Hezbollah denied the Israeli allegations, saying in a statement: "The enemy's false claims are nothing but an expression of its weakness and fragility, and a desperate attempt to evade responsibility for this crime".
Lebanese President Joseph Aoun described them in a statement on X as "civilians doing their professional duty".
"It is a brazen crime that violates all treaties and norms through which journalists enjoy international protection in war," he said.
Al-Manar described Shaib as an "icon of resistance reporting".
Shaib was widely known as one of al-Manar's war correspondents, known for his close-up coverage from frontline areas along the Lebanon-Israel border.
Al-Mayadeen said Ftouni had been distinguished by her brave and objective coverage.
Fatouni was also known for her reporting from war-ravaged southern Lebanon.
"The problem of the enemy is that they want to kill the narrative," al-Mayadeen's director in Beirut said.
"The word can never be shot."
The killings followed the death of Hussain Hamood, a Lebanese freelance journalist working for al-Manar who the Committee to Protect Journalists (CPJ) said on X was killed in an Israeli air strike on Wednesday.
At least three other reporters across the Middle East have been killed in air strikes since the Iran war began late last month, the CPJ said on Thursday.
The US military did not respond to a request for comment.
with DPA
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