SANTIAGO — Chilean riot police fired tear gas and used water cannons Tuesday to disperse violent protesters on the fringe of an otherwise peaceful student demonstration in the capital Santiago.

Tens of thousands of teachers, students, parents and sympathetic labor activists marched in downtown Santiago for the fifth time in two months to demand reforms from the conservative government of President Sebastian Pinera.

The peaceful protest came apart when a group of hooded youths hurled sticks and rocks at riot police near the presidential palace of La Moneda. Some of the youths smashed street lights and broke windows, and a car was set ablaze.

Police said some 60,000 people marched. Organizers put the number closer to 150,000.

Either way, the recent wave of student protests is the largest since democracy was restored in Chile in 1990 after 17 years of military dictatorship.

Students want the state to take over the public school system, where 90 percent of the country's 3.5 million students are educated.

The nationwide school system was broken up during the 1973-1990 military regime and handed over to local authorities. Protesters say the current system results in deep inequalities and is underfunded.

"The government is not listening to us, we want a new education system in Chile and the government proposals do not address what we want," said Manuel Soto, a protester from the University of Santiago.

"The protests will continue ... until the government gives us better education," Soto told AFP.

Chile has the highest per capita income of any country in Latin America, but the Andean nation also has one of the most skewed income disparities in the region.

Students also want more affordable higher education: most Chilean college students take out loans to go to private for-profit universities because public colleges are few and short of funding.

"I'm marching because I have two children and I can't make ends meet; they are going to be in debt for years" when they go to college, Graciela Hernandez, one of the protesters, told AFP.

Student leader Camila Vallejo hailed the protest as a "success" and called on Pinera's government to allow the Chilean people to directly decide the future of education in a referendum.

The government, however, appeared inflexible on the issue with Interior Minister Rodrigo Hinzpeter urging "the whole country" to "reflect" on the damage caused by the protests.

"When a march is held, organizers have to make themselves responsible for making sure it is peaceful," Hinzpeter said.

Police authorized the Tuesday march, unlike a protest demo last Thursday that resulted in more than 800 arrests.

Protests have been mounting since Pinera, the first right-wing president to govern Chile since 1990, announced wide-ranging education spending cuts earlier in the year.

Protests also occurred Tuesday in Chile's other main cities, including Arica, Valparaiso and Concepcion, and hundreds marched in solidarity in Argentina, where there is a large population of Chilean college students.

Unions representing public workers and copper miners announced they would join the students, a sign that the social upheaval against Pinera -- in power since March 2010, and with a 26 percent approval rating -- is broadening.