UN leader Ban Ki-moon "expresses his deep concern over the harsh sentences handed down in Bahrain to civilians -- medical professionals, teachers and others -- by the Court of National Safety," said UN spokesman Martin Nesirky. "These proceedings were conducted under conditions that raised serious questions of due process irregularities."
The 20 medics were jailed for up to 15 years on Thursday for their roles in pro-reform protests crushed in mid-March by the national safety court, under a special emergency law declared by King Hamad.
The sentences were imposed on Thursday only days after Ban had met Bahrain's king on the sidelines of the UN General Assembly in New York to discuss efforts to restore stability in the Gulf state.
"The secretary general calls for the release of all political detainees and reiterates his appeal to the Bahraini authorities at the highest level to ensure the application of due process and respect for international human rights norms," Nesirky added.
Ban discussed the Bahrain political crisis with Gulf Cooperation Council secretary general Abdullatif al Zayani on Thursday.