Saudi Arabian police shot dead a Shi'ite protester in the country's oil-producing east late on Thursday, local activists said on Friday, bringing the death toll from clashes in the restive area to 12 this year.
They said police had opened fire on protesters demonstrating about the detention of people from the Qatif district, killing 18-year-old Ahmad Matar and injuring six others.
The authorities confirmed in a statement that a man had died but contradicted the activists' account, saying a security patrol had come under fire and shot back in self defence.
The spokesman for the Eastern Province police said the routine patrol was attempting to intercept rioters who had blocked a road with burning tyres when it came under fire from several sources, including the man they shot dead. Police said he had a handgun.
Activists said security forces in two sports-utility vehicles had shot "indiscriminately" at the demonstrators in central Qatif and fired at people on rooftops.
Qatif, one of two large Shi'ite population centres in the kingdom, has suffered unrest since early 2011, with protesters complaining of persistent discrimination in the Sunni-dominated state, and at the arrest of local people.
The world's top oil exporter and birthplace of Islam adheres to the puritanical Sunni Wahhabi Muslim school, which views Shi'ites as heretical.
Saudi Shi'ites say they lack the same job opportunities as Sunnis, that their neighbourhoods receive inadequate state investment and that the authorities stop them building places of worship.
Some Qatif activists accuse the government of crushing the protests by shooting at demonstrators, intimidating locals with constant armed patrols, and detaining people without laying charges or bringing them to trial.
Saudi authorities say they do not discriminate against Shi'ites, pointing to King Abdullah's efforts to include them in the advisory Shoura Council and to his foundation this year of a centre to study different Islamic sects.
They also reject charges of heavy handed policing, saying all the shootings this year have occurred after police came under attack by rioters.
They have accused rival Shi'ite power Iran of stirring up the unrest, a charge Iran denies.
Although Saudi Shi'ites live mostly in the crude-producing Eastern Province, protests have not targeted energy production and both oil and gas facilities are heavily guarded.