Lebanon's Hezbollah said it had attacked Israeli an army position using explosive drones for the first time, prompting heavy Israeli shelling, escalating clashes at the frontier.

The Israeli army said it was striking a series of Hezbollah targets in Lebanon following several launches towards Israel, in a post on social media platform X.

Lebanon's National News Agency reported Israeli shells hitting various areas of the south along the border.

In a statement, Iran-backed Hezbollah said it had used two drones packed with explosives to attack an Israeli army command position in the disputed Shebaa Farms area at the Lebanese-Israeli border.

Meanwhile, an Israeli army spokesman said that the Iman Hussein Brigade, an Iranian-sponsored militia from Syria, has been transferred to south Lebanon to support Hezbollah.

The attack comes a few days after Hezbollah said for the first time it had used a surface-to-air missile against an Israeli drone.

Hezbollah said the drones filled with "a large quantity of explosives" had attacked the headquarters of the Israeli battalion in the Shebaa Farms area, and they had hit their targets.

Israel has held the Shebaa Farms, a 15-square-mile (39-square-km) area of land, since the 1967 Middle East war. Both Syria and Lebanon claim the Shebaa Farms are Lebanese.

Hezbollah fighters have been exchanging fire with Israeli forces across the Israeli-Lebanese border since the Palestinian militant group Hamas and Israel went to war on Oct. 7, in the deadliest escalation at the frontier since a 2006 war.

Hezbollah leader Sayyed Hassan Nasrallah is due on Friday to deliver his first speech since the onset of the violence.