The Britain-based war monitor said three strikes targeted the town of Qusayr and surrounding areas.

One strike targeted "a weapons depot and a fuel storage facility for Hezbollah in the industrial city of Qusayr", killing three and wounding five others, the Observatory claimed.

The other strikes targeted warehouses near the Lebanese border and a bridge south of Qusayr, according to the war monitor.

The official SANA news agency reported Israeli strikes on Qusayr's industrial zone and some residential neighbourhoods, saying they caused material damage.

The vast land border between Israel and Syria has increasingly come under attack by Israel since its war in Lebanon erupted last month.

The main land border, known as Masnaa on the Lebanese side, was put out of service by an Israeli strike this month.

A second crossing that connects Lebanon to Qusayr was put out of service last week by another Israeli strike.

The land crossings into neighbouring Syria have become a key escape route for thousands of people in Lebanon fleeing the war.

There are six official crossings between Lebanon and Syria but several other illegal routes exist along the porous border.