SEOUL - South Korea's government has launched a crackdown on activists who led violent protests against a free trade deal with the United States, declaring zero tolerance for street violence.

South Korean farmers clash with riot police during an anti-Free Trade Agreement and anti-government rally in GwangJu. South Korea's government has launched a crackdown on activists who led violent protests against a free trade deal with the United States, declaring zero tolerance for street violence. [AFP]

South Korea's government has launched a crackdown on activists who led violent protests against a free trade deal with the United States, declaring zero tolerance for street violence.

In a strongly worded statement, it vowed to clamp down hard not only on participants in violence but on those who stirred up unrest.

"There will be no more tolerance toward illegal protests or violence," said a statement after a cabinet meeting presided over by Prime Minister Han Myeong-Sook.

"The government will be quite thorough in pursuing and punishing in accordance with laws and principles not only those who play leading roles in illegal, violent mass acts but those who actively take part in them or pull the strings from behind," it said.

Among other measures, it said the government would sue protestors over damage sustained during illegal protests.

The statement came a few hours after police carried out surprise searches at nine offices of farmers' associations and the Coalition against Korea-US Free Trade Agreement (FTA) in five provinces.

Tens of thousands of farmers, workers and activists staged protests in 13 cities across the country Wednesday, demanding labor reform and an end to the FTA talks.

Many stick-wielding demonstrators clashed with riot police in Chuncheon, Daejeon and Gwangju. Police used water cannon and fire extinguishers to repel the protestors who attempted to storm government offices.

The violence left 63 people injured, including 35 police, and caused 720,000 dollars in property damage nationwide, police said.