Beirut: At least eight Hezbollah fighters were killed in a drone strike in the eastern Syrian desert, where pro-government forces are engaged in a grinding battle against the Daesh, a monitoring group said Monday.

The Britain-based Syrian Observatory for Human Rights said a drone struck a position of the Lebanese militant group, which is fighting alongside President Bashar Al Assad’s forces.

A Hezbollah official confirmed the strike but not the toll. The official was not authorised to speak to the media so spoke on condition of anonymity.

It was not immediately clear who was operating the drone.

Unmanned aerial vehicles are now widely used in Iraq and Syria, by armies and militant groups alike.

Israel has been targeting Hezbollah’s convoys in Syria with growing regularity, saying it cannot allow advanced weapons provided by Iran to be sent to Lebanon.

Iran has sponsored and supplied Hezbollah since establishing the group in the 1980s to fight Israel’s occupation of south Lebanon.

The strike also comes one day day after Hezbollah leader Hassan Nasrallah accused Israel of pushing the region into war.

He added that Israeli Prime Minister Benjamin Netanyahu was working with US President Donald Trump’s administration to undermine the Iran nuclear deal and start a regional war.

He warned Israel not to underestimate Hezbollah’s capabilities.

Last month, Israel began massive exercise simulating conflict with Hezbollah in the country’s north—the largest drill in nearly two decades.

Tens of thousands of soldiers, including thousands of reserves, took part.

Israel and the US last month accused a UN peacekeeping mission of turning a blind eye to Hezbollah smuggling arms and amassing forces on Lebanon’s southern border with Israel in preparation for war, after a conflict between both sides in 2006.

The last time the Israeli army held a drill of this volume was in 1998, when it simulated a war with the Syrian army for a week.

Israel’s strikes are typically confined to western and southern Syria, near the Lebanon and Israel border area.

It has also been accused of striking Syrian government positions.

The US has also attacked Syrian pro-government forces by air, but only once in any connection to the war on Daesh, in September 2016, when an air raid killed at least 60 Syrian soldiers.

The White House called the raid a mistake, and said it was committed to the war against the militant group.

Syrian pro-government forces have been confronted with a fierce counter-campaign after months of advances against Daeshin central and eastern Syria.

The militants briefly cut a major highway last week, isolating pro-government forces in the east and sparking a ferocious battle to win back the artery, activists said.

The Observatory said two days of fighting in the desert area left 120 Syrian troops, Hezbollah fighters and other pro-government gunmen dead.

Syria’s military has heavily relied on Russia, Iran, Hezbollah, and other Iranian-sponsored militias throughout Syria’s six-year-old civil war.