Tens of thousands of people marched toward South Korean President Park Geun-hye's office Saturday, calling for her resignation over labor reforms and changes to textbooks, UPI reported. Police officers fired water cannons and tear gas at the crowd of between 70,000 and 130,000 protesters as they approached a barricade of 700 police buses, which were coated with cooking oil so protesters could not climb over them, in the largest protest in South Korea in several years, reported the New York Times. Student protesters told reporters a new textbook Park approved for publication "whitewashed" the history of her father, President Park Chung-hee, who ruled the country in a dictatorship for 18 years until his assassination in 1979 after coming to power in a military coup. Unionized workers also had a strong presence in the crowd in opposition to labor reforms expected to benefit the country's powerful conglomerates. Among the changes are some said to make it easier to fire workers, which Park's government said are needed to help companies compete and create more jobs.