Iran's Islamic Revolutionary Guard Corps on Thursday replaced its intelligence chief Hossein Taeb, who had held the position for more than 12 years, the Guards said in a statement.
"The Guards' chief Major General Hossein Salami appointed General Mohammad Kazemi as the new head of the IRGC Intelligence Organisation," Guards spokesman Ramezan Sharif said in the statement.
Salami also appointed Taeb, who is a cleric, as his own adviser, according to the statement.
The replacement of the intelligence chief comes after the killing of a number of members of the Guards, which is designated as a terrorist group by Iran's arch enemy the United States.
Iran and US ally Israel have been engaged in a years-long shadow war but tensions have ratcheted up following a string of high-profile incidents Tehran has blamed on the Jewish state.
On June 13, Ali Kamani, a member of the Guards' aerospace division, was killed while on a mission in Khomein in the central province of Markazi, the Guards said in a statement without elaborating.
Earlier in June, Colonel Ali Esmailzadeh, a commander of the Guards' external operations unit, the Quds Force, died "in an accident in his home", according to state news agency IRNA.
And on May 22, Guards Colonel Sayyad Khodai, 50, was killed outside his home in the east of the Iranian capital by attackers on motorbikes who shot him five times.
State television in Iran said Khodai was a member of the Quds Force and that he was "known" in Syria, where Iran has acknowledged deploying "military advisers".
The Guards described Khodai as a "defender of the sanctuary", a term used for those who work on behalf of the Islamic republic in Syria or Iraq.
The Guards accused "Zionists" of being behind the assassination and vowed revenge.
Israel last week urged its citizens to leave Turkey immediately because of "possible" threats from Iranian operatives.
Media outlets in Turkey on Thursday reported the arrest of eight people allegedly working for an Iranian intelligence cell that planned to kill Israeli tourists in Istanbul.