Israeli planes bombed Syria on Friday and Sunday. The first attack, according to  U.S., Israeli and Lebanese intelligence sources, targeted some missiles bound for Hezbollah, a Lebanese militant group. (A similar Israeli strike, in January, was also thought to have targeted Hezbollah-bound arms.) The target of the Sunday attack on Damascus was less clear.

A video, posted above, shows flames at the target location, followed by an enormous explosion 20 seconds in. The Washington Post's Liz Sly reports that the video was taken from "Mount Qassioun, a landmark hill overlooking the capital on which the Syrian government has deployed much of the firepower it is using against rebel-controlled areas surrounding the city."

The BBC reports that the blast, according to a local journalist, felt like a mild earthquake and was the largest explosion Damascus has seen since fighting began in 2011. Here's the BBC's report:

Amateur video footage and eye witness testimony suggested rocket attacks had hit weapons dumps, triggering dramatic orange-flamed blasts.

The area houses numerous military facilities, including the Jamraya research centre, designated by Syria as a scientific research centre "in charge of raising our level of resistance and self-defence."

Here's another video of the blasts, taken from farther away:

Syrian state media framed the attack as an Israeli attempt to aid the rebels, suggesting that Israel's desire to destroy any Hezbollah-bound weapons was only a "pretext." While we don't know for sure what motivated the attack, Israel has worked to avoid entering the conflict in Syria. As analysts have pointed out, a sudden collapse of the Syrian regime would be unlikely to serve Israeli security interests.

This video shows some of the aftermath at the site, which appears to have been obliterated:

Syria has responded much more forcefully to this incident than to previous Israeli strikes, suggesting that it might retaliate. Still, it seems unlikely that Syrian forces, which are already locked in close fighting with rebels across the country, would want to expand the civil war to include Israel. For the time being, both Israel and Syria seem to share an interest in avoiding escalation.