HONG KONG (AP) _ Wearing yellow plastic helmets and off-white T-shirts saying ``Zero Dioxin,'' dozens of Greenpeace activists on Thursday occupied a waste barge and blocked its operation to protest against waste incineration.

Activists climbed a crane and unfurled a banner reading: ``Ban the Burn.'' Others stood atop containers on the barge.

They also hung another banner saying, ``Stop POPs. Recycle Now,'' on their flagship, the Rainbow Warrior, which was blocking the waste delivery vessel.

POPs, or persistent organic pollutants, are byproducts of incineration and industrial manufacturing that are extremely difficult to break down naturally.

Such toxins, including the carcinogen dioxin, can accumulate in humans and animals and pass from animals to humans, or mothers to babies, through the placenta or breast feeding.

A spokesman for the government's Environmental Protection Department said in a statement that Hong Kong doesn't incinerate refuse, although it does incinerate some chemical waste ``which cannot be safely treated by other processes.''

Waste handling was partially disrupted by the protest, the statement said.

Police and Marine Department officials observed the protest but made no arrests. The few workers on the barge watched in silence.

Clement Lam, a campaigner for Greenpeace China, said incineration turns potentially recyclable or reusable materials into hazardous waste.

Every three tons of waste incinerated equals one ton of toxic ash contaminated with dioxin and heavy metals, he said.

``We want the government to abandon its proposed waste burning policy'' and reallocate funds earmarked for incineration to develop a sustainable waste management strategy, he said.

The government maintains that Hong Kong is actively promoting waste reduction.

On Monday, the government said it would test dioxin levels in residents and review alternative non-incineration methods for medical waste after meeting with the Greenpeace activists.

The environmental group's flagship is in Hong Kong as part of its five-country Asian tour. It leaves early next month for Japan.