"Our military operation today is completed and accomplished," according to a statement by the Lebanese group.

Israeli "claims of preemptive action it carried out ... and the thwarting of the resistance's attack are empty claims," it added.

The group said that the explosive drones it launched from Lebanon flew to their intended targets in Israel.

Earlier, Hezbollah said its fighters "began an air attack with a large number of drones" sent across the border, followed by more than 320 Katyusha rockets launched at "enemy positions."

The Lebanese movement stated in a statement that its attack was an "initial response" to the killing of the group’s military commander Fouad Shukr, adding that it had "ended with total success."

The first phase targeted "Israeli barracks and sites, to facilitate the passage of offensive drones towards their target deep inside the Israeli entity," the group noted, confirming that the drones successfully crossed "as planned."

The statement mentioned 11 Israeli sites targeted by Hezbollah, including the Meron, Zaatoun, Al-Sahl, and Ein Zei Tim bases, in addition to two military bases and two military barracks in the occupied Golan Heights.

Hezbollah also said that Israel’s claims of disrupting its operation with this morning’s preemptive strikes in southern Lebanon “contradict the facts on the ground and will be refuted” by the group’s leader Hassan Nasrallah later on Sunday.

Nasrallah will speak at 6pm (15:00 GMT) addressing the latest developments, according to a statement by the group.

However, Israel insisted that it has thwarted a large-scale Hezbollah attack.

The Israeli military said its fighter jets have destroyed thousands of Hezbollah rocket launchers "aimed toward northern Israel and some were aimed toward central Israel."

​An Israeli military spokesman, Nadav Shoshani, said the fire from Hezbollah was "part of a larger attack that was planned and we were able to thwart a big part of it this morning."

The government declared a 48-hour state of emergency. The aviation authority said that, by 7am (0400 GMT), flights had resumed at Israel's main international airport after a brief suspension.

Lebanon's Ministry of Health said three people were killed Sunday in Israeli raids in the country's south.

Earlier, a member of the Amal Movement, which is allied with Hezbollah, was killed in an Israeli strike in Khiam.

Hezbollah has traded near-daily cross-border fire with Israeli forces throughout the Gaza war, in a campaign Hezbollah says is in support of Palestinians.

Attacks in the Israel-Lebanon border area since October have killed more than 600 people on the Lebanese side, mostly Hezbollah fighters, but including at least 131 civilians, according to an AFP tally.

On the Israeli side, authorities have announced the deaths of at least 23 soldiers and 26 civilians, including in the Golan Heights.