BEIRUT (AP) — A Hezbollah commander and several fighters have been killed inside Syria, a Lebanese security official said Tuesday, a development that could stoke already soaring tensions over the Lebanese militant group’s role in the civil war next door.

Hezbollah’s reputation has taken a beating over its support for the Syrian regime, but any sign that the group’s fighters are taking part in the battle raises fears that the conflict could expand into a wider fight engulfing the region.