BOISE, Idaho (AP) — A decision by Iranian officials to transfer an American pastor to a notoriously violent prison has heightened concern among relatives and energized lawmakers pushing for his immediate release.

Thirty-three-year-old Saeed Abedini was convicted and sentenced earlier this year to eight years in prison for creating a network of Christian churches in private homes in Iran. Until recently, he was being held in a prison with other political detainees. But family members and human rights officials say Abedini was moved Sunday to an extremely brutal prison outside Tehran.

Abedini's wife Naghmeh (NAHG-meh) Abedini says she fears even more for her husband's life and is urging American and international leaders to act. On Thursday, 23 U.S. senators sent a bipartisan letter asking President Obama to engage in direct talks with Iran.