Iran has barred reformist former president Mohammad Khatami from leaving the country. A pro-reform website said the ban was ordered ahead of a trip he planned to make to Japan for a nuclear disarmament conference. The website did not provide details of any reasons given for the travel ban. Mr Khatami had been invited to attend the annual nuclear disarmament conference in Hiroshima. The former president has been the target of criticism by regime hardliners since he backed former prime minister Mir Hossein Mousavi against incumbent Mahmoud Ahmadinejad in last June's presidential election.