ISIL Attacks Behind the Lines

Tiyas airport after attack

In the narrow neck of regime-held territory between Palmyra and Homs,  'Islamic State 'destroys Syria airbase' used by Russia' 23rd May 2016

A strategically significant Syrian airbase, used by Russia, appears to have been almost completely destroyed - according to new satellite imagery exclusively seen by the BBC. The Tiyas facility - near the recently re-captured city of Palmyra in Syria - was repeatedly hit - with the so-called Islamic State presumed to be behind the attack. Four Russia combat helicopters and around 20 supply trucks were destroyed in the bombardment. It is not clear if any people died.

Perhaps it was too early to celebrate the capture of Palmyra. Those helicopters were presumably there for something.

UPDATE 25th May 2016
'Russian military denies ISIS destroyed its helicopters in Syria' Russia Today: 24 May, 2016