Iran claimed to have broken a Mossad spy network that was seeking information about its nuclear programme and planning to carry out bombings and assassinations.
Last week, businessman Ali Ashtari was executed after being accused of spying for Israel. The semi-official Fars agency put out a story saying that the 45-year-old had been arrested two years ago and confessed to spying for Israel using security and telecommunications equipment. Israel denied all claims.
An Iranian nicknamed "The Blogfather" has also been arrested and accused of spying for Israel. Hossein Derakhshan, who holds joint Iranian-Canadian citizenship, returned to Iran three weeks ago, having left for Canada in 2000 with his wife.
Using his Canadian passport, the 33-year-old visited Israel in 2006 "to be a bridge between the Iranian and Israeli governments".