KFAR SHOUBA, Lebanon (Reuters) – Hizbollah guerrillas fired rockets and mortar bombs at Israeli posts in the Shebaa Farms area on the Lebanon – Israel  border on Wednesday, witnesses said. Hizbollah confirmed it attacked three Israeli posts in the occupied area. Israeli security sources said mortar bombs slammed into an Israeli army post in the first serious incident for over a month.Israeli forces retaliated with artillery fire, Hizbollah’s al-Manar television reported.Black smoke could be seen rising from posts in the hilly area, but there was no immediate word on casualties.Hizbollah, backed by Iran and Syria, was instrumental in ending Israel’s 22-year occupation of southern Lebanon in 2000. But the two foes have clashed sporadically in the Shebaa Farms since.The United Nations says Israel’s withdrawal from Lebanon is complete and the Shebaa Farms is Israeli-occupied Syrian land. Lebanon and Syria say the area is still-occupied Lebanese soil.