Saudi Arabia said it arrested several "troublemakers" in its oil-rich Eastern Province on Friday while an activist said police wounded and detained protestors there after a peaceful demonstration.
Among those arrested was Mohamed al-Shakhouri, one of 23 people wanted by the security forces, the official Saudi Press Agency quoted an Interior Ministry spokesman as saying.
The activist, who said he witnessed the unrest but declined to be named for fear of retaliation from the authorities, told Reuters that protestors marched for three hours in Qatif city. Some minority Shi'ite Muslims in the area complain of official neglect and discrimination, which the government denies.
"During the march there was no police presence and when it was over the armored vehicles started entering the city, and that is when the protesters began to block roads with flaming tires and throw Molotov cocktails," he said.
Police on the armored vehicles then started shooting at the protesters in the early hours of Friday, injuring around 14 including Shakhouri who was arrested, the activist said.
Mansour al-Turki, the Interior Ministry spokesman, told Reuters the gathering did not exceed 300 people and said the arrests of the "troublemakers" had nothing to do with the gathering, which occurred in a different part of the city.
"The troublemakers blocked the roads and the police received many calls of complaint. There was no live firing and there weren't any injuries. Some were arrested and they will be investigated," he said.
Most of the country's Shi'ites live in the Eastern Province and some complain their religious ceremonies are banned or interfered with by Sunni authorities, and that they lack opportunities for work and education.
The government has pointed to efforts to include Shi'ites in a "national dialogue" started by King Abdullah last decade, the appointment of Shi'ites to an advisory Shoura Council and a relaxation of policy to allow them more freedom to worship.
It views protests among its Shi'ite minority in the context of tensions with Shi'ite power and regional rival Iran, which it accuses of fomenting the unrest. It says it has only used force when its security forces have been physically attacked.
Early this month, prominent Shi'ite cleric Nimr al-Nimr, wanted for "sedition", was arrested after being shot in the leg by police in an exchange of fire, prompting demonstrations.
In mid-July, Saudi security forces shot and killed a man who was among a group that opened fire and hurled a fire-bomb at a police station in the province, while four members of the security forces were wounded in a separate attack by masked gunmen on motor-bikes who fired at two patrols, according to official media.