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 hard-liners 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.