Thousands of protesters hurled firebombs, battled riot squads and stormed three police stations in the southern city of Kwangju Monday in the latest wave of anti-government unrest, police said.

Students shouting "Down with the military" and "Drive out the Yankees" smashed windows and doors of the stations in the city before they were driven off by poice, authorities said.About 3,000 protesters later battled police near Chonnam University after trying to march off campus.

Students surged out of the university gates and pelted police with rocks and firebombs that exploded in showers of blazing gasoline. Police in riot gear drove them back with tear gas.

Police said 23 protesters had been arrested, but declined to say whether there were injuries.

The clashes came as radical groups continued to press for a full investigation into the army's bloody suppression of a 1980 revolt in Kwangju in which at least 191 people were killed.

Radicals have clashed with police for six straight days in Kwangju, 165 miles south of Seoul. Hundreds of students from colleges across the nation have poured into the city in recent days to take part in protests.

Other parts of South Korea were reported quiet Monday, a national holiday marking the birth of Buddha.

On Sunday, 1,200 students hurled rocks at police near Chonnam University. Police in riot gear fired tear gas to drive the protesters back into the school.

National police remained on nationwide alert against renewed protests. Riot police squadrons guarded key government buildings in Seoul and other major cities.

A series of demonstrations last week were the worst political unrest since nationwide anti-government violence last summer forced the government to agree to presidential elections and broad reforms.

Radical students and dissidents took to the streets on the May 18 anniversary of the Kwangju uprising and called for the overthrow of President Roh Tae-woo's government.

Protesters contend that Roh, a top general in 1980, played a key role in suppressing the revolt. They demand that he be investigated and punished.