Seoul (AFP) - Thousands of South Korean workers and civil servants rallied in Seoul on Friday in response to a nationwide general strike call against government labour reforms.

The Korean Confederation of Trade Unions (KCTU) said more than 260,000 people across the country participated in the one-day strike, including health workers, teachers and factory employees.

The Labour Ministry said only 34,000 workers across the country had actually walked out, most of them employees of South Korea's second-largest automaker, Kia Motors.

After a rally outside Seoul City Hall, some 10,000 workers marched peacefully in the streets, causing a traffic jam for two hours.

Riot police, backed by water cannons, erected tight barricades with scores of buses on the roads leading to the presidential office, but there were no clashes.

"This government is trampling all over labour rights. We must struggle hard and crush attempts to crackdown on labour unions," senior KCTU official Dan Byung-Ho told the crowd gathered outside City Hall in central Seoul.

President Park Geun-Hye's conservative administration is seeking to push through a reform plan that it argues will introduce much-needed flexibility to a rigid labour market.

The unions say the reforms would make it easier for companies to dismiss workers, cut wages and hire more temporary workers.

KCTU wants a hike in the minimum wage and for the government to withdraw plans to rein in expenditure on civil service pensions.

The government has declared the strike illegal on the grounds that civil servants are barred from taking collective industrial action unrelated to their duties.