Reports from the Washington Post
state that American and Lebanese officials have said that Hezbollah has increased its support for the Assad regime. Among other things they have been actively dispatching military advisers into the war ravaged Syrian state to aid Assad's forces in the fighting.
It is clear that the Hezbollah militia and the Iranian Revolutionary Guard Corps are involved in Syria and do back Assad in his fight against the various oppositional rebel forces. However aside from the claims of these officials it is not yet known if these groups have directly participated in combat operations against the Syrian rebels. However the Washington Post quotes an anonymous Lebanese government official who claims that the Hezbollah has "been quite involved in a combat role, quite involved in fighting."