Hezbollah accused of backing Syria's Assad
27 October 2012 Last updated at 09:00 BST
The US has accused pro-Syrian groups in Lebanon - including Hezbollah - of providing training, advice, and logistical support to the Syrian military, raising fears that the conflict could spread beyond Syria's borders.
Hezbollah denies any involvement in Syria's civil war beyond helping refugees.
But many Lebanese people living on the country's open border with Syria are already caught up in the violence and say they have a right to defend themselves.
Wyre Davies reports.