Industrial countries criticized a draft global warming pact Saturday for not making stronger demands on major developing countries as tens of thousands of banner-waving protesters demanding "climate justice" marched toward the U.N. conference.
As night fell on the Danish capital, police said they rounded up more than 600 people in a preventive action against a group of youths dressed in black at the tail end of the mostly peaceful demonstration.
A police officer received minor injuries when he was hit by a rock thrown from the group and one protester was injured by fireworks, police said.
Initial reaction to the negotiating text submitted Friday underscored the split between the U.S.-led wealthy countries and countries still struggling to overcome poverty and catch up with the modern world.
The tightly focused document was meant to lay out the crunch themes for environment ministers to wrestle with as they prepare for a summit of some 110 heads of state and government at the end of next week.
U.S. delegate Jonathan Pershing said the draft failed to address the contentious issue of carbon emissions by emerging economies.
"The current draft didn't work in terms of where it is headed," Pershing said in the plenary, supported by the European Union, Japan and Norway.
But the EU also directed criticism at the U.S., insisting it could make greater commitments to push the talks forward without stretching the legislation pending in Congress. Both the U.S. and China should be legally bound to keep whatever promises they make, said Swedish Environment Minister Anders Carlgren.
China has made voluntary commitments to rein in its carbon emissions but doesn't want to be bound by international law to do so. In China's view, the U.S. and other rich countries have a heavy historical responsibility to cut emissions and any climate deal in Copenhagen should take into account a country's level of development.
Environment ministers started arriving in the Danish capital Saturday for informal talks before world leaders join the summit late next week.
On the chilly streets outside, police assigned extra squads to watch protesters marching toward the suburban conference center to demand that leaders act now to fight climate change.
Police estimated their numbers at 25,000, while organizers said as many as 100,000 had joined the march from downtown Copenhagen, waving banners that read "Nature doesn't compromise" and "Climate Justice Now."
Danish supermodel Helena Christensen was in the crowd. "They will be very bad politicians if they do not hear us by now," she said about the policy-makers negotiating in Copenhagen.
Most of the demonstrators were peaceful but police detained 600-700 people in a preventive raid against a bloc of youth activists at the back of the procession, police spokesman Flemming Steen Munch said.
He said police moved in when the activists started throwing cobblestones through the windows of the former stock exchange and foreign ministry buildings and masking their faces.
Earlier, police said they had detained 19 people, mainly for breaking Denmark's strict laws against carrying pocket knives or wearing masks during demonstrations.
Delegates at the conference center gathered around flat-screen TVs to watch live footage showing riot police rounding up small groups of young people dressed in black from the back of the demonstration and tying their hands with plastic wrist restraints.
Environmental activists also rallied elsewhere in Europe and in Asia to increase the pressure on climate negotiators in Copenhagen.
Thousands marched in a "Walk Against Warming" in major cities across Australia and about 200 Filipino activists staged a festive rally in Manila to mark the Global Day of Action on climate change. Dozens of Indonesian environmental activists rallied in front of the U.S. Embassy in Jakarta.
Thousands of environmentalists staged stunts and protests in 100 piazzas across Italy, from Venice's St. Mark's Square to a historical piazza in downtown Rome. They carried banners that read "stop the planet's fever" and asked passers-by to sign a petition calling on world leaders to reach a deal to reduce emissions.
The draft distributed to the 192-nation conference set no firm figures on financing or on cutting greenhouse gas emissions.
It said all countries together should reduce emissions by a range of 50 percent to 95 percent by 2050, and rich countries should cut emissions by 25 to 40 percent by 2020, in both cases using 1990 as the baseline year.
The draft continues the system for industrial countries set up in the 1997 Kyoto Protocol by which they are legally bound to targets for emission reductions and face penalties if they fall short. It makes no similar requirements of developing countries like China and India, which have pledged to reduce the growth rate of emissions but reject the notion of turning those voluntary pledges into legal commitments.
So far, industrial nations' pledges to cut emissions have amounted to far less than the minimum.
The draft also left open the form of the agreement - whether it will be a legal document or a political declaration.
Ian Fry, the representative of the tiny Pacific island of Tuvalu, made an emotional appeal for the strongest format, one that would legally bind all nations to commitments to control carbon emissions.
"I woke up this morning crying, and that's not easy for a grown man to admit," Fry said, choking as he spoke in the plenary crowded with hundreds of delegates. "The fate of my country rests in your hands."
European Union leaders announced in Brussels this week after two days of tough talks that they would commit $3.6 billion (euro2.4 billion) a year until 2012 to a short-term fund for poor countries. Most of this money came from Britain, France and Germany. Many cash-strapped former East bloc countries balked at donating but eventually all gave at least a token amount to preserve the 27-nation bloc's unity.
Still unknown is how much the wealthier nations, such as the U.S. and Japan, will contribute.