SEOUL - Tens of thousands of South Korean workers held May Day rallies on Friday, vowing to wage an "all-out general strike" if the government pushes through with planned labour reforms.
Elsewhere in Asia, dozens of protesters in Taiwan threw smoke bombs near the presidential office during a workers' rally, while in Hong Kong domestic helpers were out in force to seek greater rights.
South Korean union leaders said more than 100,000 workers took part in two rallies in Seoul, while police put the total number of participants at 38,000.
"We will crush any government attempts to suppress labour rights with an all-out general strike," Federation of Korean Trade Unions head Kim Dong-Man told the crowd at one of the rallies near parliament.
President Park Geun-Hye's conservative administration is seeking to push through a reform plan that it argues would introduce flexibility to a rigid labour market, by making it easier to hire and fire.
Similar themes played out at a protest in Taipei attended by several thousand people who demanded that Taiwan's government enact higher pay, shorter working hours and a ban on temporary hiring.
"We threw the smoke bombs to protest and ridicule the government's chaotic policies and its inability to resolve issues such as unemployment and low pay, especially among young people," said Han Shih-hsien, an organiser of the protest.
In Hong Kong, hundreds gathered to sing songs and dance in calling for better working conditions for both local and migrant workers.
The plight of maids in Hong Kong was highlighted by the case of Indonesian helper Erwiana Sulistyaningsih, who was beaten and starved by her employer Law Wan-tung in a case that made world headlines.
Despite the Sulistyaningsih case, the Hong Kong government "did not budge" on foreign domestic workers' demands for more humane working conditions, migrant rights campaigner Joselito Natividad told AFP.
"The Hong Kong government can certainly do a lot to bring down that archaic, traditional and feudal attitude towards domestic workers," he said.