Saudi Arabia protest followed by arrests in Qatif
Security forces have detained a number of protesters in eastern Saudi Arabia, state media report.
The arrests took place in the city of Qatif after "rioters" set tyres on fire during an overnight demonstration, an interior ministry statement said.
It said there were no casualties, but witnesses said several people were wounded when police opened fire.
Among those detained was Mohammed al-Shakouri, described by the interior ministry as a wanted fugitive.
In January, he was among 23 men named as suspects in connection with the disturbances in Eastern Province.
They were accused of possessing illegal weapons, opening fire on the public and police, and of serving "foreign agendas".
The demonstration in Qatif was organised to demand the release of political detainees, including the Shia cleric, Sheikh Nimr al-Nimr.
Two people were killed at a rally against his arrest earlier this month. Witnesses said they were protesters who had been shot dead by police, but the interior ministry denied that there had been any clashes.
The oil-rich Eastern Province is home to a Shia majority that has long complained of marginalisation at the hands of the Sunni ruling family.
Protests erupted in the region in March 2011 when a popular uprising in neighbouring Bahrain, which has a Shia majority and a Sunni royal family, was crushed with the assistance of Saudi and other Gulf troops.