DUBAI (Reuters) - Gunmen shot dead at least five people in Saudi Arabia's Eastern Province, state news agency SPA reported on Tuesday, in what local residents said was an attack on Shi'ite Muslim worshippers marking one of their most important religious anniversaries.
Whatever its motive, the raid late on Monday in al-Ahsa district may test already strained relations between Sunnis and Shi'ites across the Middle East as it coincides with the annual Ashoura commemoration of Shi'ite Islam.
An interior ministry spokesman said six people had been arrested in connection with the attack in al-Dalwah village, SPA reported.
"As a group of citizens was leaving a building ... three masked men opened fire at them with machine guns and pistols," the spokesman said, according to SPA, adding that the incident was under investigation.
It gave no further details. Al-Ahsa is one of the main centres of minority Shi'ite Muslims in Sunni-ruled Saudi Arabia, who are now marking Ashoura, the holy day commemorating the death of Prophet Mohammad's grandson Imam Hussein with public ceremonies and processions.
A local rights activist said that the victims were mostly young men who were standing at the entrance of the local gathering place, known as Huseiniya, where the commemorative ceremony was taking place.
"It seems the criminals were in a hurry and opened fire on youngsters at the entrance and fled," Ali al-Bahrani a local rights activist told Reuters by telephone.
He said there were reports that Saudi security forces had found a vehicle apparently used by the attackers, with automatic weapons inside it, and arrested one person in connection with the attack.
"This seems to be the work of criminals and terrorists trying to mix cards, but security authorities seem determined to strike with an iron fist," he told Reuters.
The Saudi-owned al-Arabiyah satellite news channel said six suspects linked to the attack have been detained.
SPENT CARTRIDGES
A local online newspaper, http://www.hasanews.com/, earlier reported that six people were killed and 12 were wounded, some seriously, in what it called a "terrorist attack" on the ceremonies in the village.
Videos purporting to show the aftermath of the attack posted to social media showed a body lying in a pool of blood outside a building, with people milling around calling for help. The authenticity of the videos could not immediately be confirmed.
One of the videos showed a man holding spent bullet casings at the bloodstained entrance to what appears to be a Shi'ite place of worship.
Al-Ahsa and Qatif, another centre of the Saudi Shi'ite minority, have historically been the focal point of anti-government demonstrations in support of Shi'ites.
Shi'ites say they face discrimination in seeking educational opportunities or government employment in the majority Sunni state and that they are referred to disparagingly in text books and by some 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 allegations of discrimination.
A government census in 2001 said there were about 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.
(Reporting by Mostafa Hashem in Cairo Writing by William Maclean and Sami Aboudi; Editing by Noah Browning and Andrew Heavens)