The explosion was reported to have hit the main entrance to the security building. Initial reports listed ten Russian soldiers were killed. The explosion is reported to have been "huge" A statement released by the Syrian rebel groups of Ahrar al-Sham and Bayan on Wednesday midnight, claimed responsibility for the attack and that their statement was delayed in release because they were ensuring all of those involved in this strike were able to leave the area.
This is a direct hit aimed at the Russian forces and the regime of Bashar Assad. It shows that their attempts to fortify the province has not been completely successful. It shows also that information about critical meetings containing multiple high ranking officials is being leaked to the opposition forces. Makes one wonder who is on the inside.