The spies, one of whom was recruited five months ago, did not pose a serious threat to the movement or its military capabilities, he said.
"None of these three cases are within the first line of senior leadership. They were not in positions of sensitive responsibility ... it is impossible to touch the military and security infrastructure of the resistance and its ability to confront," he said in a televised speech.
"None of them have sensitive information that could harm the structure of the resistance."
|Lebanon's Hezbollah leader Sayyed Hassan Nasrallah addresses his supporters through a giant screen to express solidarity with the Arab uprisings and in support of their sacrifices, during a rally in Beirut's suburb, March 19, 2011|
Nasrallah said the CIA agents who hired the spies had diplomatic protection from the U.S. embassy in Beirut. He accused the CIA of recruiting the spies on behalf of Israel.
"The Israelis failed to penetrate the structure of Hezbollah so they have turned to the CIA for help," he said.
"The information that those CIA officers requested from the (members) does not interest the American administration, it is military details that interests Israel in any war," he said.
"This confirms that the American embassy (in Beirut) is a center for spying for Israel."
A spokesman for the U.S. embassy said there was no substance to the accusations. "These are the same kind of empty accusations that we have heard repeatedly from Hezbollah."
Hezbollah, which Washington designates as a terrorist group, fought an inconclusive 34-day war with Israel in 2006 during which it fired missiles deep into Israel. At least 1,200 Lebanese and 158 Israelis were killed during the war.
It is not unusual to discover spies in Lebanon but it was the first time the group, which takes prides in its ability to prevent infiltration, acknowledged that it had been penetrated.
Lebanon made a series of arrests in April 2009 as part of an espionage investigation. A high-ranking army officer, a Christian party member and telecom employees were among those detained over the last year.
Last month, Lebanese military intelligence detained a Shi'ite sheikh in southern Lebanon on suspicion of spying for Israel.
Nasrallah said the information about the spies was not intended to distance the group from a U.N.-backed tribunal investigating the 2005 assassination of statesman Rafik al-Hariri.
It is expected to accuse members of the Shi'ite group of being linked to the killing. The indictment is confidential.
Media reports have said the tribunal may issue its first indictments in September or October.
"Those (spies) are not related to the tribunal," he said, adding that none of the spies' names had been mentioned by it so no one could say "that this incident is related to the tribunal and that the group was looking for scenarios to escape the tribunal."
Hezbollah, which says the tribunal is political and an Israeli tool, has repeatedly denies any link to the 2005 killing.