Speculation time : I'd imagine this has to do with Islam Atiev getting slotted the other week and Doku Umarov being pissed off. I'd also bet that it has to do with testing the effectiveness of the security services with the Sochi games coming up and the plan to commit a campaign of terrorist attacks aimed at Sochi.
Wouldn't be suprised if Russia went and laid down some serious pain on North Caucasus in the next few months.