Protesters rally, set tires alight along highway to mark Bahrain uprising's anniversary

A Bahraini anti-government protester throws a petrol bomb toward an approaching armored police vehicle during clashes Friday, Feb. 13, 2015, in the Manama suburb of Bilad al-Qadeem, Bahrain. Protest marches were held and clashes erupted in opposition areas nationwide Friday, where many shops stayed closed as part of a three-day general strike called by the February 14 opposition youth group before Saturday's fourth anniversary of Bahrain's pro-democracy uprising. (AP Photo/Hasan Jamali) (The Associated Press)

A Bahraini anti-government protester wearing a mask to protect from tear gas fired by riot police and a national flag tied around his arm, uses a piece of plywood as a shield during clashes with police following a march Friday, Feb. 13, 2015, in the Manama suburb of Bilad al-Qadeem, Bahrain. The protester is holding up a picture of Sheikh Ali Salman, the jailed leader of the largest opposition political society. Protest marches were held and clashes erupted in opposition areas nationwide Friday, where many shops stayed closed as part of a three-day general strike called by the February 14 opposition youth group before Saturday's fourth anniversary of Bahrain's pro-democracy uprising. (AP Photo/Hasan Jamali) (The Associated Press)

Bahraini anti-government protesters use old doors as makeshift shields to provide cover for fellow protesters throwing petrol bombs at police firing tear gas Friday, Feb. 13, 2015, in the Manama suburb of Bilad al-Qadeem, Bahrain. Protest marches were held and clashes erupted in opposition areas nationwide Friday, where many shops stayed closed as part of a three-day general strike called by the February 14 opposition youth group before Saturday's fourth anniversary of Bahrain's pro-democracy uprising. (AP Photo/Hasan Jamali) (The Associated Press)

Hundreds of protesters have taken to the streets in predominantly Shiite areas of Bahrain and set tires alight along a major highway to mark the fourth anniversary of widespread protests calling for reform in the tiny island nation.

The demonstrations Saturday commemorate the start of Arab Spring-inspired protests on Feb. 14, 2011. The demonstrations were dominated by the country's Shiite majority, and sought greater political rights from the Western-allied Sunni monarchy.

Authorities crushed the protests within weeks after getting help from Saudi and Emirati security forces, but unrest continues. Young activists armed with rocks and Molotov cocktails frequently block roads and clash with police.

Bahrain is home to the U.S. Navy's 5th Fleet, and is part of the U.S.-led coalition against the Islamic State militant group.