By Angus McDowall
RIYADH, May 28 (Reuters) - A Saudi Arabian court has sentenced to death a Shi'ite Muslim convicted of sedition, rioting, protesting and robbery in the district of Qatif, home to many of the Sunni kingdom's minority sect who say they face entrenched discrimination.
The sentence, issued on Tuesday and reported by state media early on Wednesday, is the second time in a week the death penalty has been imposed on a Shi'ite involved in unrest in Qatif, located in the oil-producing Eastern Province.
The judge's decision to apply the penalty can still be challenged in an appeal court, the supreme court and then by petitioning the king.
More than 20 people have been killed in Qatif since February 2011 when large protests erupted calling for democracy and equal rights between Sunnis and Shi'ites.
Demonstrations have continued sporadically. Some funerals for local people killed by security forces have also attracted thousands of mourners.
The government has said most of those killed died in shootouts between gunmen and the security forces and that police have been regularly shot at and attacked with petrol bombs, but local activists say some were shot during peaceful protests.
Ali al-Nimr, who is 18 according to activists, was convicted of sedition, breaking allegiance to the king, rioting, bearing arms, using petrol bombs against security patrols, robbing a pharmacy and stealing surveillance cameras.
Nimr, who activists said was 17 at the time of his arrest, was also convicted of chanting anti-state slogans in illegal protests and inciting others to demonstrate, state media reported.
The conviction of Nimr, a nephew of Sheikh Nimr al-Nimr, a prominent Shi'ite cleric who is also on trial, follows that of Rida al-Rubh, 26, the son of another cleric who has been critical of the authorities.
The two are part of a group of around a dozen defendants now on trial for their part in protests and violent unrest in Qatif, including Sheikh Nimr, particularly in the village of Awamiya, where police officers and facilities have been attacked.
Sheikh Nimr's arrest in July 2012, during which he was shot in the leg, prompted protests in which three people died.
A government census in 2001 said there were around a million Saudi Shi'ites. But U.S. diplomats in a 2008 embassy cable released by WikiLeaks estimated they represent up to 12 percent of the total Saudi population, which now numbers 20 million.
Shi'ites say they face discrimination in seeking education or government employment and that they are spoken of disparagingly in text books and by some Sunni officials and state-funded clerics.
They also complain of restrictions on setting up places of worship and marking Shi'ite holidays, and say that Qatif and al-Ahsa receive less state funding than Sunni communities of equivalent size.
The Saudi government denies the charges of discrimination.
King Abdullah has appointed several Shi'ites to the 150-strong advisory Shura council and included Shi'ite leaders in "national dialogue" meetings where officials hear from representatives of different groups in society.
The authorities have also accused some of those involved in the Qatif unrest of acting on behalf of a foreign power, which officials privately identify as Iran. Activists in Qatif say that is untrue. (Reporting By Angus McDowall; Editing by Toby Chopra)