Lebanese authorities have detained a high-ranking army officer, a Christian party member and a telecom firm employee, in the latest round of arrests of people suspected of spying for Israel, a security source said.
The suspects were detained as a result of different security operations over the past week, the source said on Wednesday.
The party member, Faiz Qarem, is also a retired army colonel. He belonged to the "Free Patriotic Movement" party, which is led by retired Lebanese general Michel Aoun.
Qarem's arrest was unexpected due to the fact that Aoun's party is an ally of Hezbollah.
"They (Lebanese intelligence) are not sure yet if they were giving information to Israel. That is why they are questioning them now," he told Reuters.
Lebanon has already charged two employees working for state-owned mobile telecoms firm Alfa with spying for Israel, a charge that carries the death penalty.
'Major blow to Israel's spying networks'
The employee arrested last week worked for the state fixed-line operator Ogero.
The arrests of the Alfa employees shocked the country and sparked debates on how deeply Israel had infiltrated Lebanon's telecoms and security sectors.
Two other Lebanese have been sentenced to death for spying for Israel. President Michel Suleiman has called for severe punishment for spies and said if he receives a death sentence verdict he will sign it.
Lebanon began a wave of arrests in April 2009 as part of an espionage investigation in which dozens of people have been arrested on suspicion of spying for Israel. A brigadier general of the General Security directorate was among the high profile detentions. More than 20 people have been formally charged.
Israel has not commented on any of the arrests.
Senior Lebanese security officials have said the arrests dealt a major blow to Israel's spying networks in Lebanon and that many of the suspects played key roles in identifying Hezbollah targets that were bombed during the 2006 war.
Lebanese courts have until now handed down what were widely seen as light sentences against nationals who worked with Israeli occupation forces and their local militias. Israel ended its 22-year occupation of mainly Shiite south Lebanon in May 2000.