Iranian state-run media outlets have added $600,000 to a bounty for the killing of British author Salman Rushdie imposed in 1989 over the publishing of his book "The Satanic Verses."

The leader of Iran's 1979 Islamic revolution, the late Ayatollah Ruhollah Khomeini, issued a fatwa, or religious edict, that called on Muslims to the kill the author after his book was condemned as blasphemous, forcing him into years of hiding.

Iranian hardliners say Khomeini's decree is irrevocable and eternal after his death. A wealthy Iranian religious organization offered $2.7 million reward to anyone carrying out the fatwa and in 2012 it increased the amount to $3.3 million.

The semi-official Fars news agency published a list of 40 news outlets adding to the pot. Fars itself earmarked $30,000.

"These media outlets have set the $600,000 bounty on the 27th anniversary of the historical fatwa to show it is still alive," Mansour Amiri, organizer of a digital technology exhibition at which the money was announced this month, told Reuters.

Amiri is the head of the Seraj Cyberspace Organisation, which is affiliated to the Basij volunteer militia, allied to the elite Revolutionary Guards established to defend the values of the revolution.

The head of the militia visited the exhibition, Farsi said.

Rushdie's agent said he had no comment. Iran's Foreign Ministry was not immediately available to comment

In 1998, Iran's pro-reform government of President Mohammad Khatami distanced itself from the fatwa, saying the threat against Rushdie was over after he had lived in hiding for nine years. The book's Japanese translator was stabbed to death in 1991 and other people involved in publishing it were attacked.

But Khomeini's successor as Supreme Leader, Ayatollah Ali Khamenei, said in 2005 that the fatwa was still valid and three hardline clerics called on followers to kill Rushdie.

With the landmark nuclear deal with world powers sealed last year, followed by lifting of international sanctions, pragmatist President Hassan Rouhani is trying to end Iran's isolation with the West.

However, despite the government's willingness for wider engagement, hardline allies of Khamenei fear that opening up to the West will eventually weaken their influence and the legitimacy of the Islamic Revolution.

The deal has intensified Iran's political infighting ahead of two crucial elections on Friday.

A hardline watchdog body, the Guardian Council, has disqualified thousands of Rouhani allies, barring them from entering the race for parliament and Assembly of Experts, which has power to appoint the supreme leader.