The U.S. Central Intelligence Agency warned Lebanese security agencies two days ahead of the blast that targeted Bir al-Abed neighborhood in Beirut's southern suburbs that al-Qaida had plotted to carry out an attack in the area, a report claimed on Thursday.
According to al-Akhbar newspaper, al-Qaida-linked group transported a huge amount of explosives into Lebanon to be used in the country.
Security and political sources told the newspaper that a CIA official in Lebanon provided the army intelligence and the ISF Intelligence Branch with “delicate information” regarding the matter.
The CIA report pointed out that an al-Qaida-linked-group prepared two bombs, each weigh 7 tons, to target buildings in Beirut's southern suburbs using suicide bombers.
The report said that the group is also active in Syria.
At least 53 people were wounded in an explosion  that was caused by a booby-trapped vehicle in the Hizbullah stronghold neighborhood of Bir al-Abed on Tuesday.
Another report said that another al-Qaida-affiliated group transported around 2,000 kilograms of explosives into Lebanon to target the Lebanese army, Hizbullah, Saudi Ambassador to Lebanon Ali Awadh al-Asiri and Kuwaiti Ambassador Abdul al-Qinaai in addition to Russian and Chinese diplomats.
A third CIA report included detailed information on the head of an armed group that is responsible for firing rockets on the Bekaa city of Baalbek. 
According to the last report, the head of the group is a Syrian national, who is leading the operations from the region of Reef Damascus.
The Baalbek region and several border areas have been targeted by dozens of rockets from the neighboring country Syria.
Al-Akhbar pointed out that the heads of the Lebanese security agencies didn't inform politicians of the matter but rather stressed on the importance of obtaining the full telecom data.
Officially neutral in Syria's conflict, Lebanon is deeply divided into pro- and anti-Assad camps.
Lebanon has suffered an escalating spillover  of Syria's more than two-year conflict and Hizbullah's role in Syria has set off a mounting backlash from the rebels who threatened to target the group's bases in Lebanon if it does not withdraw its fighters.