The suicide car bomb attack in a Hezbollah-dominated area of eastern Lebanon, near the Syrian border, left two people dead, according to a new toll released Monday.
A security source said the Lebanese army detected and detonated another car bomb in the Fakiha area, five kilometres (three miles) from Al-Nabi Othman village, the scene of Sunday's attack.
According to the official National News Agency, Sunday's blast killed two people and wounded another 14.
The attack was claimed by the jihadist Al-Nusra Front in Lebanon and by a little known group, Liwa Ahrar al-Sunna in Bekaa as revenge for Hezbollah's military involvement in Syria.
The two killed were members of Hezbollah, including a local official of the Shiite militant group which has sent thousands of fighters into neighbouring Syria to support President Bashar al-Assad's army.
An earlier toll on Sunday said four people were killed but it was revised downwards.
"The blast was carried out by a suicide attacker. Hezbollah members knew he was about to carry out the attack, and tried to stop the vehicle. That was when the attacker detonated the vehicle," a security source said.
The attack came hours after the Syrian army and Hezbollah took over Yabrud, a former Syrian rebel bastion.
Hezbollah-dominated areas in eastern Lebanon and southern Beirut have suffered a series of deadly attacks, many of them suicide car blasts, since the movement acknowledged sending fighters into Syria.
On Monday, the army detonated a car that was "parked on a dirt road" and was apparently being prepared for a fresh attack.
According to the security source, troops fired at the vehicle, parked some 300 metres (yards) from a school, causing a powerful explosion.