Israel's air force carried out a drone strike in southern Syria, killing five people, while a soldier was killed and seven wounded in an air raid overnight, Syrian state TV reported.
The Israeli military did not comment on the reported casualties but said it carried out a raid on Friday morning on "part of the terror cell responsible for the rocket fire at northern Israel".
Four rockets exploded in an open field in northern Galilee on Thursday, sparking small fires but causing no injuries. It was the first time since the 1973 Middle East war that rockets from Syrian territory have slammed into Israel. There was no immediate claim of responsibility.
Syrian state TV said the Israeli drone strike on Friday targeted a "civilian car" close to a busy market in the village of Kom, killing five. Quneitra governor Ahmad Sheikh Abdul-Qader said the attack happened on the road leading to the village of Khan Arnabeh, near Kom, and destroyed the car.
Israel said it had credible information that Iran, a key backer of Syrian president Bashar Assad, was behind Thursday's rocket attack.
An Israeli military official and a foreign ministry spokesman said a commander who heads the Palestinian division of Iran's elite Quds Force, identified as Saeed Izodi, orchestrated the attack that was carried out by the Islamic Jihad group.
"The military struck the cell that carried out the shooting and the Syrian forces that allowed it. We have no intention of escalating events," Israeli prime minister Benjamin Netanyahu said.
But he added: "Those countries that are quick to embrace Iran should know that it was an Iranian commander who endorsed and directed the cell that fired at Israel."
In Gaza, the Islamic Jihad group denied involvement in the attack
Syrian state TV reported that the Israeli air raid overnight happened just before midnight in the southern region of Quneitra, killing a soldier and wounding seven.
State news agency SANA reported late on Thursday that an Israeli helicopter launched several missiles on Quneitra in the evening. It said the missiles hit the transportation directorate and the municipality building.
Syrian TV, meanwhile, said the air raids aimed to "boost the morale of terrorist organisations", claiming that Israel is backing militants in the area.
Israel and Syria are bitter enemies. Israel has avoided taking sides in the Syrian civil war, which pits Assad's government against an array of militants, including the brutal Islamic State group.