(CNN) -- A 16-year-old boy was killed at an anti-government demonstration in the city of Sitra on Saturday, Bahrain's largest opposition bloc said.
Sayed Hashim Saeed was knocked out after a tear gas canister hit him, but attempts to rescue him were disrupted by riot police, the opposition Al-Wefaq group said in a statement.
Hundreds of people were protesting the regime, the group said.
The boy was eventually taken to a hospital, where he died from his injuries, the group said.
The government did not immediately make a statement about the incident.
The group claimed that on Saturday, throughout Bahrain, thousands participated in a sit-in in front of their houses.
Eyewitnesses told CNN that police sealed off Sitra after the clashes with protesters. They reported seeing tear gas used to disperse the protesters.
Demonstrations demanding political reform and greater freedoms in Sunni-ruled, Shiite-majority Bahrain began February 14 before authorities -- backed by troops from Saudi Arabia and the United Arab Emirates -- cracked down in two waves, first in February and later in mid-March.
CNN's Samira Said contributed to this report.