BEIRUT - The Syrian government said Monday a series of Israeli airstrikes targeting its troops in retaliation for a deadly cross-border attack killed four people and wounded nine others, in its first comment on the overnight incident.
It said the attack was a "flagrant violation" of Syrian sovereignty, but in a departure from previous incidents when Israeli warplanes struck targets in Syria, the government did not vow retaliation.
Israel's prime minister on Monday warned the warring parties in Syria against any attempt to heat up tensions along the disputed frontier, hours after the Israeli air force carried out a string of airstrikes in Syria in response to the attack, which killed an Israeli teenager riding in a civilian vehicle.
Prime Minister Benjamin Netanyahu said Israel would respond with even tougher force if there are any further attacks.
"Last night we operated with great force against Syrian targets that acted against us, and if needed we will use additional force," he told members of his Likud Party. "We will continue to forcefully hurt anyone who attacks us or tries to attack us."
The Israeli military said the air raids struck nine targets in neighboring Syria.
A statement issued by Syria's Foreign Ministry said five Israeli warplanes carried out the raids, which were accompanied by mortar rounds and tank shells.
It said four people were killed and nine others wounded, adding that the attacks caused extensive damage to Syrian army positions and equipment. It did not provide further details.
The director of the Britain-based Syrian Observatory for Human Rights, Rami Abdurrahman, said the Israeli strikes destroyed two tanks, two artillery batteries and the headquarters of Syria's 90th brigade.
The Observatory collects its information through a network of activists inside Syria.
The Israeli military said "direct hits were confirmed" on the targets, which were located near the site of Sunday's violence in the Golan Heights and included a regional military command center and unspecified "launching positions."
Israel has kept a close eye on the Syrian uprising since it began in March 2011, although it has avoided backing either side. On several occasions, artillery rounds have landed on the Israeli side of the de facto border, drawing limited Israeli reprisals.
Israel also has carried out several airstrikes in Syria over the past three years, primarily targeting suspected weapons shipments allegedly destined for Hezbollah militants in neighboring Lebanon. In each of the cases, the Syrian government vowed retaliation, but refrained from taking any action.
The latest air raids, however, came after an Israeli civilian vehicle was struck by what the Israeli military said was a Kornet anti-tank missile fired from the Syrian side of the border as it drove in the Israeli-controlled Golan Heights.
A teenage Israeli boy was killed and two other people were wounded in what was the first deadly incident along the volatile Israeli-Syrian frontier since the start of the Syrian civil war.
It was not clear whether the attack was by government troops or rebels. But Israeli officials said suspicion was focused on Syria or its Hezbollah allies, since both are known to possess Kornet missiles.
Israel captured the Golan Heights, a strategic plateau overlooking northern Israel, from Syria in the 1967 Mideast war. Its subsequent annexation of the area has never been recognized internationally.
Israel has repeatedly said it holds the Syrian government responsible for any attacks emanating from its territory, regardless of who actually carries them out.
Israeli security officials, speaking on condition of anonymity because they were not allowed to talk to the media, said they did not expect the situation to escalate immediately but that it remains tense. Much would depend on Syria's response to the Israeli airstrikes, they said.
Defense officials have feared that Hezbollah or some other militant group might try to open a new front with Israel at a time when the army is carrying out a broad operation in the West Bank. Thousands of troops have been searching for three teenagers who disappeared on June 12 and are believed to have been kidnapped by Palestinian militants.
Sunday's incident occurred in the area of Tel Hazeka, near the Quneitra crossing. The Observatory said Syrian troops had shelled nearby targets on the Syrian border earlier in the day.
Israeli police identified the boy as Mohammed Krakra, 14, of the Arab village of Arabeh in northern Israel. Local media said he had accompanied his father, the truck driver, to work.