Israel’s spy agency orchestrated the assassination of at least four Iranian nuclear scientists, according to a new book by an American and an Israeli journalist.

Spies Against Armageddon: Inside Israel’s Secret Wars by Dan Raviv of CBS News and Yossi Melman, a Ha’aretz analyst, states that Mossad has undertaken several terrorist missions in Iran that targeted nuclear scientists in order to curb the country’s nuclear program.

The authors say Israeli agents “excel at accurate shooting at any speed and staying steady to shoot and to place exquisitely shaped sticky bombs.”

They also claim Israel is responsible for the cyber attacks targeting Iran’s computer systems with viruses such as Stuxnet and Flame.

Iran has repeatedly accused Israel and the United States of being behind the assassination of its nuclear scientists as well as cyber attacks against its computer systems.

Raviv and Melman maintain that these operations are very sensitive and are carried out by Mossad’s super-secret Kidon unit.

Islamic Republic authorities have recently announced that they have discovered and arrested a spy ring responsible for the assassination attempts on scientists, and earlier this year they executed another Iranian who confessed on television to having been recruited by Israeli agents to assassinate one of Iran’s nuclear scientists.