On Monday Hizb Allah fired two missiles on a hilltop position in Alman al-Qusair that had been held by Israel before its 2000 pullout from south Lebanon, the police said.
Israeli artillery opened up after this attack, firing nearly 45 shells in 15 minutes around the villages of Kfar Shuba, Rashaya al-Fakhar, Kfar Hamam and Halta, wounding two women, security sources said.
An AFP correspondent saw Israeli helicopters and other aircraft overflying Lebanese soil at low altitude.
Israeli military sources confirmed that the bulldozer had been hit but said it had suffered only material damage and the attack had caused no casualties.
Hizb Allah's Al-Manar television station said the attack on the vehicle caused casualties and that an Israeli ambulance rushed to the scene.
The strike came a week after a Hizb Allah attack in the same disputed Shebaa Farms district killed one Israeli soldier and wounded three more.
Retaliatory Israeli fire at the time hit a UN peacekeeping patrol, killing a French soldier and wounding a Swede.
The United Nations later said Hizb Allah bore the principal blame for the casualties.
Last week Israeli fire hit a UN
patrol killing a French soldier
It rejected the group's argument that attacks on the Shebaa Farms were legitimate because the district remained Israeli-occupied.
Seized from Syria in the 1967 Arab-Israeli war along with the rest of the strategic Golan Heights, the Shebaa Farms are now claimed by Lebanon with Syria's backing.