Strong blasts hit the outskirts of Syria’s capital early on Sunday, with reports saying that they were results of Israeli airstrikes on a military research center. Other sources suggest Damascus Airport was hit.

Massive explosions have been heard near Mount Qasioun in Damascus. The area hosts the Jamraya military research center, which came under Israeli attack earlier in January and marked the first incursion by Israel into Syrian airspace in six years.

A senior US official confirmed to NBC News that Israeli Air Force bombed the military research center.

The overnight Israeli strike reportedly targeted Iranian-supplied missiles to Lebanese guerrilla group Hezbollah, a Western intelligence source told Reuters. "In last night's attack, as in the previous one, what was attacked were stores of Fateh-110 missiles that were in transit from Iran to Hezbollah," the source said.

There have also been reports that the airstrikes targeted the 104th and 105th brigades of the Syrian Republican Guards, a source told RT Arabic.

A senior Israeli official confirmed to AFP that the Israeli airstrike on Syria was carried out near Damascus Airport overnight, targeting Iranian missiles destined for Lebanon's Shiite Hezbollah movement.

"The attack was very close to the airport, the target was Iranian missiles which were destined for Hezbollah," he said.

Mount Qasioun and Damascus Airport are located in different parts of the city, so if both were targets of airstrikes, this would likely require a more complex coordinated attack.

There are reports of gunfire shots heard in outskirts of Damascus, apparently indicating that some rebel groups tried to seize the opportunity and went into offensive amid the commotion caused by the airstrikes. However, no major breakthroughs on their part were reported.

The rebel offensive however may give the Syrian government grounds to further accuse Israel of supporting the Syrian armed opposition by saying they had foreknowledge of the Israeli airstrikes and were prepared to move out.

REPORT OF NO POWER IN ENTIRE AREA OF DAMASCUS DUE TO ISRAELI AIR FORCE STRIKE THIS NIGHT — חברה הצלה ארץ ישראל (@IsraelHatzolah) May 5, 2013

Syria's Ministry of Health did not confirm if there were any deaths or injuries.

RT has managed to speak to a local journalist, who requested anonymity, for a report on the latest developments.



“When the explosion happened in Damascus, all the houses were shaken. There was dust everywhere. Right now we’re receiving more information about the attack, which targeted the Jamraya military research center," he told RT. "Everyone woke up, most of the people ran downstairs – to make sure they are safe. Now we are getting more information. The sound of the explosion was heard everywhere in Damascus. People are scared.”

Rumors fly as official info remains scarce

While no official casualty number has been made public, rumors on Syrian social media say that at least 300 soldiers stationed at Mount Qasioun have been killed and hundreds of others injured, the journalist said. Many Syrians are calling for retaliation as the possibility of a full-scale war with Israel is speculated upon.

During the attack, one Israeli jet was reportedly shot down by Syria's Air Force, according to Hezbollah's Manar TV channel, citing security sources in Damascus. Two Israeli pilots of the downed IDF jet have been taken to a military area in Damascus under Assad’s control, according to reports in Lebanese and Syrian media.

War spillover into region feared

There has been no immediate official comment from Israel. "We don't respond to this kind of report," an Israeli military spokeswoman told Reuters.

Israel’s Prime Minister Benjamin Netanyahu convened the security cabinet on Thursday night to approve the airstrike, a source told Reuters.

Israeli military has called up several thousand reservists earlier this week for what it called a "surprise" military exercise on its border with Lebanon, AP reported.

Earlier this week, the IDF deployed two Iron Dome batteries near the cities of Haifa and Safed in northern Israel, amid tensions along the border in that area.

Video footage uploaded onto the Internet showed a massive ball of fire rising into the sky. RT could not immediately verify the authenticity of the videos.

“Until we get a clear picture of what exactly was targeted it’s difficult to speculate why the targeting took place. I’d say that the US gave Israel the green light for the previous attack in past months and reportedly gave them an OK to launch future strikes. So this probably isn’t something that happens on the spur of the moment,” news editor at antiwar.com Jason Ditz told RT.



“Of course, Syria is unlikely, being in the middle of a civil war, to launch much of retaliation against Israel directly, but at the same time this probably undermines some of the more Islamist factions in the Syrian rebels especially with reports that they are benefiting from these airstrikes,” he added.

In the meantime Netanyahu is leaving on Sunday afternoon for a five-day trip to China that will focus on economic ties and regional issues such as Iran, Syria and Egypt. His departure however was delayed by two hours to make room for a security cabinet meeting, according to Haaretz newspaper.

Airstrikes escalating

The Israeli Air Force conducted an airstrike on Syrian territory on Friday, reportedly targeting a shipment of advanced missiles. Unnamed US officials claimed that the missiles had been en-route from Iran to Lebanon’s Hezbollah.

Among the varying descriptions of the actual rockets, Fateh 110s have come up, which are advanced enough to strike Tel Aviv from southern Lebanon and, therefore perceived as a threat by Israel.

On Saturday, before Sunday’s overnight strike, US President Barack Obama stated that Israel has the right to defend against the transfer of advanced weapons to Hezbollah.

"I'll let the Israeli government confirm or deny whatever strikes that they've taken," Obama said in an interview with the Spanish-language network Telemundo.

Israel's Defense Minister Moshe Ya’alon earlier told journalists that any alleged delivery of Syrian weapons to Hezbollah would be considered a "red line." Ya'alon then said Israel would not permit "sophisticated weapons" to fall into the hands of "Hezbollah or other rogue elements."

Obama has also said in the past that the crossing of a ‘red line’ would warrant further action from outside. This was in relation to the possibility that Assad forces may have used chemical weapons against Syrians – a claim that is still being investigated, with no evidence so far.

Nonetheless, US Defense Secretary Chuck Hagel announced on Thursday that the US may now consider arming the Syrian opposition – something the US has shied away from openly doing in the two years since the start of the Syrian uprising.

Asked directly if the administration was reconsidering its position on that option, Hagel said "yes". "Arming the rebels — that's an option," he said. "We must continue to look at options."

The conflict in Syria has entered its third year. According to UN estimates, at least 70,000 people have been killed since the uprising against President Bashar Assad began in March 2011.