BEIRUT, Lebanon - Hezbollah fighters successfully ambushed a group of Syrian rebels over the weekend as they infiltrated Lebanon through a rugged mountain area along the Syrian border, killing about 30 of them, a Hezbollah commander confirmed Tuesday.

The rebel unit entered Lebanon early Saturday though a smuggler route outside the eastern Beqaa Valley town of Nahle, where Hezbollah maintains a number of training camps and arms depots, local residents have told Lebanese media. The Hezbollah commander, who spoke on condition of anonymity because he wasn't allowed to speak with the media, said the rebels were infiltrating the area to fire rockets into nearby Shiite villages in retaliation for Hezbollah's military involvement in the neighboring Syrian civil war.

"Our unit from [nearby] Britel knows the area very well and was waiting for them," the commander said. "They were slaughtered."

The Hezbollah source described the rebels as members of the Nusra Front, an al-Qaeda-linked group often cited as among the most militarily competent of the rebel forces in Syria.

Hezbollah chief Hassan Nasrallah has repeatedly cited the presence in the Syrian rebellion of groups like the Nusra Front - which follows an ideology that believes Shiite Muslims are heretics - as a justification for his group's involvement to protect Shiite villages from just such rocket attacks.