First, there is no official number, and we cannot have an official number. The only way we know, and the only way it became official, that Hezbollah was fighting in Syria was when they buried several Hezbollah fighters and said they were martyrs. No war zone was declared in Lebanon, so where did these martyrs fall?
A few weeks later—and I have the exact dates. The first time Hezbollah declared that they had martyrs, who fought without any fight, was in early October, and then a few days later, on October 8, Hassan Nasrallah, the head of Hezbollah, officially declared that these people had died or had fallen as defenders of the jihad in Syria, because they were doing their jihad in Syria.
What we are sure of is that these fighters are fighting with the regime against the Syrian opposition, against the people of Syria who are requesting their freedom and their democracy. What has linked Hezbollah to Syria is jihad, which means it is really a non-political fight. It's really a confessional fight, and this is where today Hezbollah is no longer a Lebanese fighter in Syria, but rather is playing the role of Iran directly in the Syrian regime.