Protesters demonstrated throughout the capital of Manama to mark the failed Arab Spring demanding political reforms on the Sunni-ruled, Shiite-majority island nation, CNN reported.
Bahrain's main Shiite opposition party, al-Wefaq, said the teen died when he was hit by birdshot fired by Bahraini security forces.
Authorities said they are investigating the death.
"We encourage people to remain calm and not spread unfounded rumors until more information becomes known," a statement from the government said. "We reiterate the call ... upon parents to supervise the whereabouts of their children at all times in order to ensure their safety. We urge parents to keep their children at school and go about their daily routine."
The attempted uprising two years ago failed to gain the same traction as similar movements in Tunisia and Egypt after a crackdown by authorities backed by troops from Saudi Arabia and the United Arab Emirates, CNN reported.