SANTIAGO — Police fired tear gas and water cannons on at least 100,000 demonstrators in the Chilean capital Thursday, and arrested 13 during the biggest protest in two months demanding educational reforms.

Angry protesters hurtled sticks, rocks and metal objects like pies as police responded from armored vehicles in the violent culmination of what had been a peaceful, festive and colorful demonstration, the sixth of its kind.

WATCH: Education protests turn violent in Chile

A police officer was hurt and 13 people were arrested. Organizers estimated a crowd of about 200,000 people participated in the demonstration, while local media gave an estimate of 100,000. No official figures were immediately available.

Rioting broke out at the end of a sprawling demonstration on the streets of downtown Santiago, including a huge crowd waving flags and banners outside La Moneda presidential palace.

A cellphone shop was ransacked and protesters attacked police at the Brazilian embassy in Santiago in an attempt to breach the security barriers and occupy the building. The embassy is located just across the Ministry of Education in the center of the capital.

"This is historic. Since the return of democracy, we haven't seen anything this big," said Giorgio Jackson, a student leader.

The unrest came two weeks after some 70,000 people took to the streets calling for greater government investment in public education, which now totals 4.4 percent of Chile's gross domestic product compared with the seven percent of GDP for developed countries recommended by the United Nations.

"The strikes and protests are legitimate, but that's not how we will improve education. You need work, study, responsibility and engagement for that," said President Sebastian Pinera, a conservative multimillionaire businessman.

Students and professors want the Chilean government to retake control over the Chilean public schools that educate 90 percent of the country's 3.5 million students.

Control of the public school system was ceded to local municipalities during the 1973-1990 military dictatorship of General Augusto Pinochet.