ABU DHABI (Reuters) - A court in Bahrain sentenced a policeman to seven years in prison for the fatal shooting of a Shi'ite protester during the political unrest in the Gulf Arab kingdom in 2011, the state news agency BNA reported on Friday.

Ali Abdulhadi al-Mushaima was the first person to die in the violence that erupted in staunch U.S. ally Bahrain last February when thousands of Bahrainis, mostly from its Shi'ite majority, took to the street demanding democratic change in the Sunni-led monarchy.

"In dealing with one of the instances of rioting in the (Daih) area, the accused fired from a birdshot gun, injuring the victim with wounds that claimed his life," Nawaf Hamza, head of the Public Prosecution's Special Investigation Unit, was quoted as saying.

The death of Mushaima and another protester, Fadhel Salman Matrook, prompted Bahrain's King Hamad bin Isa al-Khalifa to give a televised speech in which he said a committee would investigate the killings.

An independent commission said thirty-five people died during the unrest and two months of martial law that followed, but the opposition puts that number at more than 80.

The government, which brought in troops from Saudi Arabia and other Gulf Arab states to help quell the unrest, rejects the figures and has accused opposition groups of being linked to Shi'ite power Iran.

Widespread and excessive force, including confessions under torture, was detailed in the commission led by Cherif Bassiouni, a respected United Nations human rights lawyer, which published its findings and recommended measures to stop them.

The Bahrain government says it has taken steps to address the brutality of security forces by dismissing those responsible and introducing cameras at police stations to monitor abuses.

The Shi'ite opposition wants a constitutional monarchy and a greater say in the running of the country, including an end to decades-old discrimination against them holding jobs in the army and security forces. The government denies discriminating against Shi'ites.

(Reporting By Raissa Kasolowsky; Editing by Jon Boyle)