Seoul  - Opposition lawmakers and security guards clashed in South Korea's parliament on Saturday during a sit-in by the members of parliament (MPs) and their supporters, according to media reports.

A scuffle erupted as more than 150 guards tried to clear the main meeting room of the National Assembly in Seoul of several lawmakers and their supporters.

The official Yonhap news agency said one MP and about 20 aides and guards were lightly injured.

The Democratic Party (DP) MPs had been staging a sit-in to protest against plans by the ruling conservative Grand National Party (GNP), which has a majority, to adopt controversial legislation.

Access to the parliamentary speaker's podium has been blocked for more than a week already amid disagreement over the ratification of a free trade agreement with the United States and various other media bills.

The social democratic opposition wants the adoption of the trade pact postponed until the government provides adequate measures to protect local farmers.

The GNP hopes to ratify the trade agreements and adopt many other draft laws by Thursday, Yonhap said.

South Korea's opposition lawmakers often resort to sit-in protests to block legislation, with violent clashes in parliament not uncommon.

The GNP holds 172 seats in the 298-member National Assembly. (dpa)