DUBAI (Reuters) - Thousands of Shi'ite Muslims turned out for the funerals of two men killed during protests triggered by the arrest of a prominent Shi'ite Muslim cleric in Saudi Arabia's oil-producing Eastern province, witnesses said on Wednesday.
Mohamed al-Felfel and Akbar al-Shakhouri were shot dead on Sunday in what an Interior Ministry spokesman described as a "criminal act" after protests broke out following the arrest of Shi'ite cleric Sheikh Nimr al-Nimr on sedition charges.
Activists say the two men were killed by police snipers stationed on rooftops, a report denied by the Interior Ministry.
The cleric's arrest and the killings have raised the temperature in one of the most volatile regions in Saudi Arabia, where the kingdom's Shi'ite Muslim minority is concentrated. The U.S. embassy in Riyadh has warned its citizens to exercise caution when travelling to the area.
The Eastern Province is home to a Shi'ite population that has long complained of discrimination and marginalisation by the Sunni ruling family. The Saudi government denies any discrimination.
Saudi Arabia, the world's largest oil exporter and a key regional ally of the United States, has escaped the "Arab Spring" protests that forced leaders in Tunisia, Egypt, Yemen and Libya out of power.
An activist who said he was taking part in one funeral in the village of Awamiya on Wednesday night talked of tens of thousands of mourners in the street. It was not possible to verify the figure.
An Interior Ministry spokesman confirmed the funeral was taking place but gave no estimate of the number of attendees.
The activist said marchers chanted "Down with the House of Saud", referring to the kingdom's ruling family, and "Down with Mohammed bin Fahd", the governor of the Eastern Province.
The crowd also carried Bahraini flags and chanted "Qatif and Bahrain are one people", said the activist, in reference to Shi'ites in the neighbouring island kingdom who have led an uprising demanding reforms.
Earlier, activists posted videos of what they said was Felfel's funeral late on Tuesday in Qatif, showing large crowds, many of them men in white robes, chanting "Down with Mohammed bin Fahd" in reference to the governor of the Eastern Province.
They also emailed pictures of men holding placards criticising the royal family. It was not possible to independently verify the authenticity of the recordings and photographs or to determine where or when they were taken.
The Rasid news website said Saudi security forces stayed away from the funeral procession, which passed through the main Abdulaziz Street in the centre of Qatif.
Interior Ministry spokesman Mansour al-Turki said security forces had worked hard to ensure the safety of the mourners.
"Some trouble-seekers took advantage of the gathering to hide in their midst and divert the context of this event which led the security forces to do their duty to keep the peace and ensure the safety of those participating in the funeral procession," he told Reuters.
Shi'ite community leaders have appealed for calm during the funerals, urging people to avoid being drawn into a situation that could lead to bloodshed.
"This tense and difficult period that Qatif is passing through necessitates that we all work together to safeguard our society from any security deterioration, God forbid, to protect lives and sanctities," read a statement signed by a group of local notables, including Sheikh Abdallah al-Khuneizi, a former Shi'ite religious court judge.
The statement also appealed to security forces to exercise restraint and patience to get past a "dangerous and critical period".
Saudi Arabia acknowledged that some protests had taken place after Sheikh Nimr was arrested, but the Interior Ministry said there were no clashes between protesters and police.
"In the aftermath of the arrest ... a limited number of people assembled in the town of Awamiya," an Interior Ministry statement said. "Gunshots were overheard in the town. However, there was no security confrontation whatsoever."
Nimr is seen as a leading radical cleric promoting the Shi'ite cause. He had been arrested and released before.
His brother said police had ambushed him on his way home from a farm he owns. Activists posted pictures on the Internet of a grey-bearded man they identified as Nimr inside a vehicle. He was covered with what appeared to be a blood-stained white sheet.
Activists said Nimr had been taken to the capital Riyadh.
Shi'ites say it is hard for them to get government jobs or university places, their neighbourhoods are run down, and their places of worship are often closed down.
The government denies such accusations.
Qatif is located next door to Bahrain, an island kingdom that has been in turmoil over demands by its majority Shi'ites for political reforms by the Sunni ruling Al Khalifa family.
Both Bahrain and Saudi Arabia accuse non-Arab Shi'ite Iran of fomenting unrest among their Shi'ite populations.
Protests broke out in the Eastern Province region in March 2011 when unrest in neighbouring Bahrain was quashed with the assistance of Saudi and other Gulf troops.
Reporting by Sami Aboudi, Asma al-Sharif and Andrew Hammond; Editing by Ralph Boulton and Kevin Liffey