Bahrain Mirror (Reuters): Iran rejected terrorism charges raised against it in an annual U.S. State Department report, Iranian media outlets reported on Sunday, saying the Islamic Republic merely supported nations fighting for freedom.

"The legitimate struggle of nations which are occupied ... are not examples of terrorism, and such charges in the American report are rejected," said Foreign Ministry spokesman Hossein Jaberi Ansari, quoted by state news agency IRNA.

Ansari in turn condemned "U.S. military interferences and destructive support for terrorist groups in Iraq, Afghanistan, Syria, Libya and Yemen", the agency said.

As in previous years, the report cited Iran as the world's biggest state sponsor of terrorism, saying Tehran supported conflicts in Syria and Iraq, and was implicated in violent Shi'ite opposition raids in Bahrain.

Bahrain has accused Iran of fomenting unrest in its country and of supplying weapons to Shi'ite militants behind several bomb attacks on security forces. Iran has denied the claims.

The U.S. global terrorism report said on Thursday that the number of terrorist attacks around the world declined last year for the first time since 2012, and that such attacks were becoming more decentralised and diffuse.