Police in Bahrain fired tear gas and clashed with students on Tuesday in a raid on a secondary school in the capital, Manama, AP reports.
According to the news agency, officers stormed the Jabreya school for boys after students staged a protest demanding the release of fellow student, 17-year-old Hassan Humidan, who was arrested at the school on Monday.
Activists tweeted pictures purporting to show clouds of tear gas and spent canisters at the school.
According to the BBC, unconfirmed reports said there had been injuries.
About 100 people have been arrested this month amid growing tensions and boosted security as the country prepares to host next week's Formula 1 race.
Activists and protesters have called for the Grand Prix to be called off because of Bahrain's human rights record.
