Police fired water cannons to disperse raucous demonstrators in the Philippines, and students clashed with authorities in South Korea as labor tensions flared Monday during May Day celebrations.
In Manila, several protesters and a firefighter were injured after demonstrators threw rocks and tried to break through police lines in the direction of Malacanang presidential palace.
Police retaliated with water canons against the hundreds of leftist demonstrators. Seven members of a labor group were arrested.
Leftist labor groups contend President Joseph Estrada has followed pro-employer policies despite campaign promises to side with labor in the fight against poverty.
Violence also erupted in South Korea, where authorities tried to prevent militant students from joining a rally by workers in downtown Seoul.
The mood was more placid in Japan, where the rallies are usually more like picnics than protests, but the country's near record high unemployment added a sense of urgency.
In Hong Kong, where unemployment remains severe despite the territory's impressive rebound from a 15-month recession, 100 protesters marched to the downtown government headquarters.