Humiliation for Powell at Earth Summit

The US secretary of state, Colin Powell was booed, heckled and jeered as he tried to defend America's environmental record on the closing day of the world summit in Johannesburg today.

Delegates from non-governmental groups in the audience repeatedly interrupted his speech, chanting: "Shame on Bush".

Several people held up banners reading: "Betrayed by governments" and "Bush: people and planet not big business". At least one person was removed from the hall by security. Mr Powell was visibly annoyed by the repeated outbursts. At one point he answered back: "I have now heard you."

The South African foreign minister, Nkosazana Dlamini-Zuma, who was chairing the meeting, asked hecklers to stop. She said the outbursts were "totally unacceptable". Dissent filled the hall when Mr Powell criticised the government of Zimbabwe for exacerbating the food crisis in that country and pushing "millions of people to the brink of starvation".

While his speech was delayed by the protesters, he soldiered on, and finally delivered his message that "the US is taking action to meet environmental challenges, including global climate change".

America has been strongly criticised by foreign leaders and environmental activists for its rejection of the Kyoto protocol, which is widely regarded as crucial in the bid to halt global warming.

The US argues that the agreement would prove too expensive for its polluting industries and would cost millions of US jobs. It also complains that it is unfair because poor countries are not bound to cut carbon emissions.

The Bush administration has faced renewed criticism at the summit because of its resistance to binding targets to increase the use of renewable energy. President George Bush himself refused to attend the event.