Also charged were two sheiks, Ahmad Gharib and Hashem Minqara. The Syrian intelligence officer was charged in absentia, as was another Syrian.
A Lebanese government informant, Mustafa Houri, has also been charged, The (Beirut) Daily Star reported.
Two car bombs were set off outside mosques in the Lebanese capital last week, killing 47 and wounding 500, the government said. A group within Lebanon with ties to Hezbollah, which supports Syrian President Bashar Assad's regime in that country's civil war, is suspected of carrying out the attacks.
Prosecutors said Minqara, head of the pro-Assad group, was charged for withholding information about the terror attack after being picked up for questioning Thursday. Gharib is a close associate.
Houri allegedly tipped off police about the bomb plot but prosecutors questioned his motive for doing so and charged him, as well.
Information on the two Syrians charged wasn't immediately available.