It seems as per russian media russian marines guarding a base in Latakia destroyed a small group of Daesh militatants:http://fortruss.blogspot.si/2015/09/rus ... syria.html
September 21, 2015
Translated by Kristina Rus
Russian marines engaged in a fight with militants of the Islamic State near the Syrian city of Latakia.
According to news agency "Fresh Wind", on Saturday night to Sunday morning members of ISIS tried to mount an attack on the airbase, however, they were ambushed.
During the battle, the Russian military claims to have killed some militants, and some captured.
The agency also notes that the ambushed militants had a detailed plan of the air base and clear satellite images marked with key military installations.
As announced on September 20th by "MILITARY INFORMANT" On the night from September 19 to 20, our marines guarding the Russian military base, located near the settlement of Latakia (Syria), discovered a group of militants walking in the direction of the base, numbering up to 8 people. The decision was made to destroy the enemy, after all, our intelligence knew about the plans of the militants for organizing the attack on the Russian base in Latakia with mortars and small arms.
As a result of the clash, three militants were killed, two captured, and the rest retreated. During the search of the prisoners plans of the airbase and satellite images with the marked important points of the base were found.
Also worth of note is that Russia sent few aircraft to Syria to protect their bases (as per most reports). Now pic's of Su-27 series fighters, approx a dozen Su-25 attackers series and probably few Su-24 series bombers were seen. 4 Su-24's were filmed in formation with Il-76. As for planes themself Su-24 could also be aircraft of SyAF which operates the type quite succesfully and Su-25's could be from IRIAF which has 2 squadrons of them operating from Iraq. IRIAF is extremly active and is flying huge number of missions against Daesh in Iraq and Syria as per some reports at least 2 times the number of US coalition combined (Iranian AF types known to be active Su-24, Su-25, F-4's). Su-27's are a bit more difficoult to explain.
IMHO if for the protection of their bases it can only be from aircraft from certain neighbour state known for bombing Syrian army positions (end generally acting as Daesh AF in the south Syria) and whose panicked PM recently visited Moscov.