BEIRUT — A Syrian opposition group said Monday that more than 42 soldiers were killed and 100 others remained unaccounted for in reported Israeli airstrikes Sunday outside Damascus, providing the first unofficial accounting of casualties in attacks that raised concerns about an escalation of the more-than-2-year-old Syrian conflict.
In Israel, meanwhile, officials continued to predict that Syrian retaliation was unlikely, as Israelis debated how much further their forces could go without sparking an unwanted war with Syria or its allies.
The casualty estimates came from the British-based Syrian Observatory for Human Rights, a pro-opposition monitoring organization. Syrian authorities have released no official casualty figures from Sunday’s massive pre-dawn bombardment outside the capital.
The Syrian Foreign Affairs Ministry has said there was “widespread destruction” of both military and civilian areas when Israeli airplanes struck three military sites. Footage on state television has shown smoldering ruins, gutted buildings and charred vehicles, all said to be the result of Sunday’s attack.
The explosions lasted for more than an hour, witnesses said, rattling windows and sending fire balls above heavily fortified Mount Qasion, which towers over the capital. Some of the blasts probably resulted from stored munitions that detonated after the missiles struck.
The strikes were believed to be the second Israeli attack on Syria in recent days, following a reported airstrike Friday.
Israel has not confirmed the attacks, but officials have indicated privately that they were intended to destroy sophisticated missiles destined for Hezbollah, the militant group based in neighboring Lebanon that is a close ally of Syria and Iran.
Syria called the Israeli explanation a pretext and denied that weapons were being transferred outside the nation’s borders. Syria said it would respond in time to what it called an unprovoked act of war against the government of President Bashar Assad.
Israeli officials stressed that their nation was not taking sides in Syria’s bloody civil war and acted strictly to disrupt the Hezbollah arms pipeline from Syria. Before the strike, analysts said, Israeli strategists calculated that Syria and Hezbollah were unlikely to retaliate and risk an even larger Israeli response.
Well before Sunday’s attacks, some Israeli defense experts had been urging the government to take advantage of Assad’s weakened position by destroying his arsenal of sophisticated weapons, including those not earmarked for Hezbollah. Some fear the arms could fall into the hands of militant Syrian rebel factions or a future Islamic government bent on attacking Israel.
“For the past few months various security officials have been toying with the idea that the chaos in Syria has created a one-time opportunity to get rid of its problematic arsenal without having to pay with all-out war,” wrote Alex Fishman, defense analyst for Israel’s leading newspaper Yediot Aharonot.
Though Assad might respond with some artillery fire or rocket strikes, “the price that Israel will pay, the assessment goes, is worth the risk,” Fishman wrote. “In exchange, it will be able to relax for a good many years.”
But some in Israel cautioned that Israel should not overplay its hand or allow itself to be seen as intervening directly in the Syrian conflict.
Danny Yatom, former chief of the Israeli spy agency Mossad, on Monday warned against an Israeli “euphoria” that might lead commanders to believe they can strike Syria at will, expanding targets beyond advanced weapons heading for Hezbollah.
“If we exploit the chaos in Syria and try and do a few other things,” Yatom told Israel Radio, “that would be a mistake because the greater the quantity, the more Assad and Hezbollah will have to respond.”
Commercial air traffic in northern Israel, which had been suspended Sunday as a precaution, was expected to resume Tuesday, a sign that Israeli officials were not anticipating retaliation.
“There are no winds of war,” declared Maj. Gen. Yair Golan, who heads the Israeli army’s northern command.
Late Monday, two mortar rounds fired from Syria landed in the Israeli-occupied Golan Heights, causing no casualties, the military said. Israeli officials were quick to dismiss the projectiles as “errant” shells, rather than a deliberate attack on Israel.
In Syria, meantime, battles flared on several fronts. Rebels said their forces shot down a military helicopter in the east, killing eight soldiers. Fierce fighting was reported for a second consecutive day at the Mannagh military air base in northern Syria. Rebels have been trying for months to overrun the strategic facility, situated near the Turkish-Syrian border.