Doctors and nurses given up to 15 years in jail for treating people injured during uprising in Gulf kingdom

Twenty Bahraini medics who treated activists wounded during anti-government protests were jailed for between five and 15 years in sentences that were immediately denounced by medical bodies and human rights groups around the world.

The sentences were handed down by a military court set up to handle the trials, which stemmed from an Arab spring-inspired uprising in the country in February and March. It was crushed with the help of armies from Saudi Arabia and the Gulf states. Thirteen of the doctors and nurses received sentences of 15 years in prison, while another seven received terms of five to 10 years.

All of the accused were charged with committing crimes against the state, during an uprising they insist was peaceful and popularly inspired.

Most worked at the Salmaniya Medical Centre in Manama, which became a focal point of the tiny Gulf kingdom's uprising. Government officials claimed it had been transformed into a base for a plot to overthrow the 200-year-old monarchy.

The formal charges were for stealing medicine, possessing weapons and occupying a government hospital. The medics were also accused of "inciting hatred to the regime and insulting it, instigating hatred against another sect and obstructing the implementation of law, destroying public property and taking part in gatherings aimed at jeopardising the general security and committing crimes."

The doctors, all of whom denied the charges, were among dozens arrested for joining protests led by Bahrain's Shia majority against the government headed by the country's ruling Sunni minority.

The protests were quickly cast by Bahrain's government as a sectarian plot ordered by Iran. The crackdown that followed the demonstrations led to the imposition of martial law and the Gulf Co-operation Council sending troops to the island state.

Amnesty International described the sentences as ludicrous. "It appears that the real reason for targeting these health workers was the fact that they denounced the government crackdown on protesters in interviews to international media," said the group's Africa and Middle East deputy director, Philip Luther. "The ruling government clearly wants to send a message that anybody perceived as advocating political reforms will be dealt with severely."

British Foreign secretary William Hague led the international condemnation. "These sentences appear disproportionate to the charges brought," he said. "These are worrying developments that could undermine the Bahraini government's moves towards dialogue and the reform needed for long-term stability in Bahrain."

Several of the doctors, interviewed by the Guardian this year, say they were cast into a political role by an increasingly violent crackdown launched by government troops in mid-February in an attempt to oust protesters from their hub in central Manama — a roundabout then known as Pearl Square.

A medic who was sentenced on Thursday said the events of 17 February – a particularly savage assault on the roundabout – had changed the nature of the uprising.

"That day changed my life," the medic said. "I felt bad seeing my own people treated like animals.

"In April, my fears came true and I was taken from my house by more than 30 masked men with guns in front of my son, whom I had to leave alone.

"I was physically and emotionally abused, blindfolded and handcuffed. They beat me – with their hands and legs, with a hose, and gave me electric shocks. They threatened to rape me. They threatened to kill me so that I would confess to false accusations. I was sexually harassed and humiliated."

Britain joined international bodies in attacking a lack of transparency in the military court, which was set up using emergency powers. "I call on the Bahraini judicial authorities to follow due process carefully and transparently. Cases before the special tribunals should be transferred to regular civilian courts," said Hague.

In a separate case before the military court, a man was sentenced to death for running down and killing a policeman. The sentences came a day after the tribunal upheld an appeal by 21 activists, including senior figures from the main opposition bloc, al-Wefaq, against life sentences they received for allegedly plotting to overthrow the monarchy.

Around 30 people have been killed in a series of clashes with security forces this year. At least 1,000 people have been detained. Bahrain's king, Sheikh Hamad bin Isa Al Khalifa, called for dialogue during the summer. This was immediately boycotted by opposition groups.

He has also announced a commission of inquiry into claims of mass discrimination against the country's Shia majority, which is banned from much of the establishment.

Hundreds of Shia demonstrators who joined sweeping pro-democracy demonstrations in February have complained that they have since been sacked or suspended from their jobs in both the private and public sector.