Johannesburg, South Africa ? Unfurling banners and shouting “Shame on Bush,” dozens of activists at the World Summit heckled Secretary of State Colin Powell on Wednesday as he defended America’s record on the environment and helping the developing world. Thirteen activists were dragged from the room.

Boos from the rear of the summit’s main hall repeatedly interrupted Powell’s five-minute speech to an audience of 1,500 government leaders and delegates.

“The American soul has always harbored a deep desire to help people build better lives for themselves and their children,” Powell said. “We have always understood that our own well-being depends on the well-being of our fellow inhabitants of this planet Earth.”

The United States joined 190 other nations on the summit’s last day Wednesday in adopting an action plan aimed at improving the lives of the poor and reversing the destruction of the planet.

But Washington was widely accused in 10 days of tough negotiations of shirking past commitments and trying to avoid new ones.

Government officials and activists have strongly criticized the United States for rejecting the 1997 Kyoto Protocol, which seeks to reduce emissions of carbon dioxide and other gases that trap heat in the atmosphere. Many countries view the accord as crucial for reversing global warming, which has been blamed for cataclysmic storms, floods and droughts.

President Bush has said the United States is taking other actions to fight climate change, but the international agreement’s strictures are inappropriate and too costly for the U.S. economy.

Washington also has been hammered by some here for opposing binding targets to increase the use of solar and wind power and other renewable energy sources, and for Bush’s decision not to attend.

During Powell’s speech, dozens of American, Australian and other activists in the audience jeered and shouted “Shame on Bush.” Some held up banners reading “Bush: People and Planet, Not Big Business.”

South African Foreign Minister Nkosazana Dlamini-Zuma, who was chairing the session, banged her gavel and yelled at the hecklers to stop. Security forcibly removed 13 people from the hall.

Powell looked annoyed, answering back at one point: “I have now heard you,” before going on.

The heckling started when Powell criticized Zimbabwe for pursuing land reform policies that have exacerbated the food crisis there and pushed “millions of people to the brink of starvation.” The comments brought some cheers from the audience as well.

He also criticized Zambia, which is also facing widespread hunger, for rejecting genetically engineered corn that Americans eat every day.

However, much of his speech focused on America’s commitment to the developing world and the environment.

“We have reaffirmed the principle that sound economic management, investment in people and responsible stewardship of our environment are crucial for development,” Powell said.

The conclusion of the summit was delayed by a couple of hours as delegates negotiated the wording of a political declaration to accompany the plan. “We declare our responsibility to one another, to the greater community of life and to future generations,” it said.

Commitments to focus attention on issues including foreign occupation, terrorism and HIV were added at the 11th hour before the declaration was adopted with applause.