Thousands of radical students pelted riot police with firebombs and rocks today in Seoul and other cities, and demanded the arrest of former President Chun Doo-hwan on corruption charges. It was the worst political clash in Seoul since major anti-American protests last summer. Many police officers and students suffered cuts and other injuries from firebombs and rocks, but there were no overall figures. Police did not say if any protesters were arrested. In Seoul, about 3,000 students fought police in four areas near Chun's house in a fashionable residential suburb. Clashes were also reported in several provincial cities. ``Arrest Chun Doo-hwan. Punish (President) Roh Tae-woo,'' students in Seoul shouted as they hurled firebombs and repeatedly charged police despite a dense fog of tear gas. About 9,000 police were posted along streets and alleyways leading to Chun's house to repel the protesters. Police used tear gas whenever students tried to break through their lines. Traffic came to a standstill and most shops in the areas were closed as the fighting persisted for several hours. Many pedestrians wore gauze masks or put hankerchiefs over their noses to filter out the acrid tear gas. In front of Sogang University at the center of Seoul clashes, about 700 students, brandishing hundreds of firebombs, repeatedly charged about 500 riot police who were blocking their march. Police retaliated with tear gas. Firebombs exploded in showers of orange flames near or amidst columns of police, who deflected the missiles with shields and put out blazes with hand-carried extinguishers. Several blocks away, near the house of opposition leader Kim Dae-jung, another group of 500 students battled police with rocks and firebombs. Kim's house is about eight blocks from Chun's. In the southern city of Kwangju, about 2,000 students held campus rallies or took part in street protests to demand Chun be punished for alleged corruption and human rights violations. In Chunchon and Ansung in eastern and central South Korea, dozens of students also attacked with firebombs a police station and a government party office. No injuries or major damage was reported. News reports said thousands of students had held anti-Chun rallies on their campuses to prepare for a march on Chun's house. Fighting erupted at some schools as students tried to march out. Anti-government demonstrations have been escalating in recent weeks as radical students organized ``save-the-nation suicide squads'' and threatened to raid Chun's house to press for his arrest and punishment. The anti-Chun march was part of anti-government strategies by radical students, who are also calling for an ouster of President Roh. They argue that hte Roh government is dragging its feet on a probe of alleged corruption and other scandals involving the ex-president, his family members and associates. Roh and Chun, both former army generals, have been close friends since they were classmates at Korea Military Academy in the 1950s. Roh succeeded Chun, who stepped down following protests at the end of a seven-year term in February. Chun has come under public fire for his alleged misuse of power during his tenure. One of his brothers, Chun Kyong-hwan, has been sentenced to seven years in prison for taking bribes and embezzling millions of dollars worth of official funds. Former Seoul Mayor Yom Bo-hyon, a close confident of Chun, was also sentenced to a five-year jail term last month for taking bribes and illegally helping the business of some family members of the ex-president. Chun is also under investigation for his alleged role in militarily suppressing a 1980 civil uprising in the southern city of Kwangju that resulted in the deaths of about 200 people.