Riot police officers arrest a demonstrator during a protest to mark the 'Day of the Young Combatant' in Santiago, 28 Mar 2008

Police and protesters clashed Friday in the Chilean capital of Santiago, on the eve of a day commemorating two brothers who were killed during the country's military dictatorship.

Some 300 protesters, mainly students, blocked traffic on Santiago's main avenue.  Police used water cannons and tear gas to disperse the protesters, who threw rocks back.

At least 150 people were arrested.  News reports say many of those detained are minors.

March 29 is known as the "day of the young combatant" in honor of two brothers who were killed on that day in 1985 during a rally against the dictatorship of Augusto Pinochet.

Chile's president, Michelle Bachelet, has called for the brothers to be commemorated without violence.

Friday's protests also were aimed at the government and its economic policy, which the demonstrators say manipulates the education system to favor the wealthy and exclude the poor. 

Last August, authorities arrested at least 740 people who took part in mass protests in Santiago over the government's social and economic policies.  Labor unions organized the protests, saying workers should get a larger portion of profits from Chilean industry.  Chile is the world's biggest copper producer and has benefited from high prices for the metal in recent years.

President Bachelet has pledged to take advantage of revenues from copper exports to improve education and conditions for the poor.  Chile has one of Latin America's most prosperous economies.

Some information for this report was provided by AFP, and Reuters.