It looks like they did a true tit-for-tat, blowing up a target with a missile (or a planted explosive). Reporting is early, so it's hard to tell, just like with the Ismael Haniyeh situation.

The photo is from Tel Aviv (and off Facebook, lol), it seems to show the response. Haven't seen any photos of the explosion itself yet, but I'm sure those will be coming out shortly.

It could have also been some other group, but that seems unlikely.