State media said on Sunday that a senior member of Iran's Revolutionary Guard Corps (IRGC) was assassinated outside of his home in an unusual assassination in Tehran.

Colonel Sayad Khoda was "one of the defenders of the shrines," according to the semi-official Tasnim news agency, referring to military soldiers or advisers who Iran claims battle on its behalf to preserve Shiite sites in Iraq or Syria from groups like the Islamic State (IS) organization.

Two individuals on a motorcycle opened fire on Khodai, according to Tasnim, citing a reliable source.

While no one has claimed responsibility for the murder, the semi-official ISNA news agency stated the Guards had uncovered and arrested members of an Israeli intelligence service network.

The Israeli Prime Minister's Office, which supervises Mossad, refused to comment on the events in Tehran.

"The sworn enemies of the holy system of the Islamic Republic of Iran once again showed their evil nature with the assassination and martyrdom of one of the members of the IRGC troops," stated Iranian Foreign Ministry spokesperson Saeed Khatibzadeh.

Since 2010, at least six Iranian scientists and academics have been slain or attacked, with several of the attackers riding motorcycles. The crimes are believed to have targeted Iran's controversial nuclear program, which the West claims is intended to produce a bomb.

Iran disputes this, citing the benign nature of its nuclear program, and has condemned the murders as terrorist activities carried out by Western intelligence agencies and the Mossad. Israel has refused to comment on these allegations.

In a statement issued by the semi-official Fars news agency in April, Iran's intelligence ministry stated it had captured three Mossad spies.

Since the beginning of the Syrian civil war, Iran has sent fighters to Syria to defend its friend, President Bashar al-Assad, against Sunni insurgents.

Also included among the "defenders of the shrines" are Afghan and Pakistani volunteers.