TEHRAN (AFP) - A Sunni militant group in Iran has claimed it kidnapped a man working at a nuclear facility and has threatened to spill his secrets if members of the group held by Tehran are not released. Jundallah (Soldiers of God) said on its website junbish.blogspot.com late on Saturday that it was holding hostage Amir Hossein Shirani, an 'employee at a nuclear plant in Irans central province of Isfahan. Mr Shirani has important information, especially about senior Iranian nuclear experts... and release of his confessions will cost the Iranian regime dearly, it said in a statement, without adding when Shirani was abducted. Jundallah has demanded that Tehran free what it said were more than 200 Sunni and Baluch political prisoners and members of the group held in Iranian jails, the statement added. It warned that failure to do so 'within a week would lead to releasing to the public the information gathered from Mr Amir Hossein Shirani, so the world finds out more about the Iranian regimes secret nuclear activities. The website said Shirani was being held in the mountains of the southeastern Sistan-Baluchestan province bordering Pakistan and Afghanistan, an area known for drug smuggling and tribal unrest.