The United Nations has condemned the sentencing in Bahrain of 20 doctors and nurses to prison terms of between five and 15 years.

The medical staff, some of whom trained in Ireland, say they were treating protesters hurt in clashes with government forces during unrest there in March.

However, the Bahraini government said they were involved in the protests.

UN leader Ban Ki-moon has strongly criticised "harsh" prison sentences ordered against the medical workers and called for the release of all political prisoners.

Mr Ban "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 Mr Ban had met Bahrain's monarch 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," Mr Nesirky added.

The Tánaiste and Minister for Foreign Affairs, Eamon Gilmore, said the Irish Government would raise the sentences with the authorities in Bahrain through diplomatic channels.