Saudi Arabia vowed to use "an iron fist" after 11 members of the security forces were injured by attackers during unrest in a Shiite Muslim town in the east, Bloomberg said citing a report of the official Saudi Press Agency.

The government accused an unnamed "foreign country" of seeking to undermine the stability of the kingdom as a result of the violence in Awwamiya, in which the assailants, some on motorcycles, used machine guns and Molotov cocktails, the Riyadh-based news service reported late yesterday. A man and two women were also injured, the news service said.

Saudi Arabia, the world's largest oil supplier, escaped the mass protests that toppled the leaders of Egypt and Tunisia this year and spread to the Saudi neighbors of Yemen and Bahrain. There were some rallies earlier in the year in mostly Shiite eastern Saudi Arabia, including Awwamiya and al-Qatif village.