DALWA, Saudi Arabia, Nov. 4 (UPI) -- Three gunmen opened fire in a Dalwa, Saudi Arabia, Shiite shrine, killing five people and injuring nine, witnesses and the state news agency said.
The attack in the country's eastern al-Ahsa district, a center for Saudi Arabia's Shiite minority, occurred on a day of Shiite religious significance, honoring the Prophet Muhammad's grandson, Imam Hussein.
The state news agency offered no motive for the attack, saying only, "As a group of citizens was leaving a location, three masked men opened fire at them with machine guns and pistols."
It added an investigation by police was underway.
The incident could increase tension in Shiite-dominated regions in the oil-rich eastern part of the country. The minority group often accuses the Sunni-ruled government of discrimination, although the government denies it.
Shiites are a frequent target of attack by Sunnis in Iraq; the Shiites are regarded there as heretics.
