Not the first time that they've pulled this off:

Hamas continued its rocketing of innocent Israeli civilians on Monday afternoon, with a Grad-type rocket slamming into an empty kindergarten in Ashdod in the most recent attack. No one was wounded in the attack, though massive damage was caused to the building, and thirteen people were treated for shock. Also Monday afternoon, nine people were lightly wounded when two Grad rockets were fired at Ashkelon. A building was damaged in the attack, which came moments before two more rockets hit open areas in Beersheba and another hit Ashdod. Several people were treated for shock following the attacks.

Dozens of missiles - some scoring direct hits - have been indiscriminately launched at Israeli civilians in the last 24 hours. Hamas's mid level soldiers are bragging about how they have even bigger rockets and other "tools" that they haven't used yet. The good news: given that the IDF's Gaza intel was top-notch and that they've already captured some Hamas operatives, Israel might well know what's coming. The bad news: Israel might well know what's coming.

References:
* Hamas Now Literally Bombing Israeli Schoolhouses [MR]
* Grad-type rocket slams into empty Ashdod kindergarten [JPost]
* 32 rockets fired at southern Israel [YNet]
* Hamas' military wing: We have tools that have yet to be used [YNet]
* At least five Hamas operatives captured during ground op [JPost]
* Hamas's "Big Surprise" - An Attack On Dimona That Will Trigger A Full-Blown Regional War? [MR]

Previously:
* 10 Mortars Fired At Israeli Schools And Hospitals In Last 48 Hours
* 12 Rockets Fired At Israeli Schools And Hospitals Monday
* Grad-type rocket slams into empty Ashdod kindergarten [JPost]