The Lebanese government says it has arrested the leader and some members of an al-Qaeda cell, thwarting an attack on Italy's embassy in Beirut.
Lebanese officials say these are the first al-Qaeda arrests in Lebanon
Three hundred kilos (660 lbs) of explosives are said to have been recovered following a joint Italian, Syrian and Lebanese operation.
Interior Minister Elias Murr said the group had received funds from Europe.
The group is also said to have been planning to attack Ukrainian and Lebanese targets in Beirut.
Mr Murr said the leaders of the plot were Ahmed Salim Mikati and Ismail Mohammed al-Khatib, both Lebanese.
He said eight Lebanese and Palestinian accomplices were also arrested.
Lebanon's Prosecutor General Adnan Adoum said the leaders "had links to al-Qaeda".
Mr Murr told a news conference that al-Khatib "is an al-Qaeda operative... his role was to recruit fundamentalist youth to carry out operations against coalition forces in Iraq".
He said the group was also planning to assassinate employees working in Western embassies in Lebanon.
The Italian Defence Minister, Antonio Martino, issued a statement praising Italian military intelligence, and thanking the Lebanese and Syrian security services for their co-operation.
Groups linked to al-Qaeda have issued threats against Italy and killed Italian hostages in Iraq in response to the Italian government's support for the US-led war in Iraq.