11.   Shiite opposition groups have been pressing the Sunni Muslim-dominated government for political reforms and improved social conditions.

12.   Shiite opposition groups have been staging protests to press their demands for political reforms and improved social conditions.

13.   Shiite opposition groups have staged protests to press demands for political reforms and improved social conditions.

14.   The Bahrain Freedom Movement, which appears to be the broadest-based Shiite opposition group, made its latest claim in a statement faxed from London.

15.   The Iranian-backed Al-Dawa Party, a Shiite opposition group, claimed responsibility shortly after the shooting.

16.   The Iranian-backed Al-Dawa Party, a Shiite opposition group, claimed responsibility.

17.   The groups included two main Kurdish rebel groups in northern Iraq, and several Shiite opposition movements.

18.   The Iranian-backed Al-Dawa Party, a Shiite opposition group, claimed responsibility shortly after the attack.

19.   The Shiite opposition also includes the more radical Islamic Front for the Liberation of Bahrain, which operates out of London and Beirut.

20.   The Shiite opposition launched a campaign against the government two years ago demanding broader political and social opportunities.