A protester holds up a placard during a demonstration demanding the release of prisoners they say are held without trial, in the Gulf coast town of Qatif March 10, 2011. Credit: Reuters/Stringer
* HRW accuses Saudi Arabia of arresting peaceful protesters
* Says Oct 3 clashes sparked by arrest of two elderly men
* Saudi accused "foreign power" of instigating violence
Human Rights Watch accused Saudi Arabia of arbitrarily arresting peaceful activists in its Eastern Province, home to a large Shi'ite Muslim minority, and of sparking recent clashes there with the detention of two elderly men.
Hundreds of Shi'ites in Saudi Arabia protested in February to demand the release of activists. Those have been followed by small, sporadic demonstrations that have led to more arrests.
Saudi government statements have blamed the violence on a "foreign power" -- a phrase often used to describe the Shi'ite country of Iran.
The Arab kingdom, which follows an austere Sunni school of Islam, said 14 people, including 11 members of its security forces, had been injured by demonstrators who shot guns and threw petrol bombs during clashes in Awamiya, an Eastern Province village last week.
In a statement, the Saudi Interior Ministry vowed to end the protests with "an iron fist".
HRW said last week's demonstrations began after security forces arrested two elderly men to force their sons to surrender to police.
"Saudi authorities should immediately stop arbitrary arrests of relatives, rights activists, and peaceful protesters," said Christoph Wilcke, senior Middle East researcher at HRW in a statement posted on the rights group's website.
Saudi Arabia's Shi'ite population is mostly based in two oasis districts of the Eastern Province, Qatif on the Gulf coast where Awamiya is located, and al-Ahsa southwest of the provincial capital al-Khobar.
The kingdom says it is home to 1.3 million Shi'ites out of a population of 19 million Saudi citizens. Human rights groups say there are around 2 million Shi'ites in the kingdom.
This week tensions between Iran and Saudi Arabia rose another notch after the United States said it had uncovered a plot by two men linked to Iranian security forces to assassinate the Saudi ambassador in Washington. Tehran has denied the charges.