An estimated 100,000 activists crammed into an exhibition grounds off a Mumbai highway, with dozens of colorful demonstrations pushing their way over a pavement littered with fliers for causes from all continents.

The most common cause at the World Social Forum, however, was opposition to US President George W. Bush, whose portrait was depicted across the wooded venue in assorted states of defacement.

Arundhati Roy, the Indian novelist and political essayist, launched the forum late Friday with a call for activists to select two US companies associated with the Iraq war and launch a worldwide campaign to shut them down.

The World Social Forum is designed as a counterweight to the World Economic Forum of business and political leaders in Davos, Switzerland, which is due to open as the Mumbai meet closes Wednesday.

It is the fourth World Social Forum but the first to be held outside Brazil.

On Saturday, a small band of leftists opened the Mumbai Resistance, an alternative to the World Social Forum, which they said had failed to stop the United States from going to war to depose Iraqi strongman Saddam Hussein.

"The WSF must take a clear position against the Americans and support the Islamist resistance in Iraq," said Itirina Vana, a 22-year-old Austrian selling the latest issue of the magazine Soviet at the Mumbai Resistance grounds.

"Some groups in the WSF are against the terrorists," she said with regret.

While most delegates at the Mumbai Resistance were Indian, the participants' list was a kaleidoscope of far-left movements from Turkey to Italy to Chad.

Organisers, however, said the Mumbai Resistance drew 2,000 people, far below the attendance across the street.

At the World Social Forum, activists ranging from pacifist South Korean students to Indian street vendors handed out leaflets, marched to drumbeats and staged impromptu theatre to press their causes.

Jose Bove, the radical French farmer and emblem of the anti-globalisation movement, urged activists to find alternatives to the World Trade Organisation, which he charged was dictating rules for agriculture even at the village level.

Jeremy Corbyn, a British member of parliament, used the forum to urge a common front against Israel's occupation of the Palestinian territories.

Corbyn was joined by Palestinian civil society activist Mustafa Bargouti, who charged that Israeli Prime Minister Ariel Sharon was biding time as the United States was unwilling to press him during a presidential election year.

"I urge the world to note our sufferings and force Israel to stop building the wall that Sharon is building in our territories," Bargouti said.

Critics of the World Social Forum, which has drawn little interest from the Indian media, say the gathering focuses only on abuses in the world without offering concrete alternatives.

Individual organisers of the Mumbai meeting have charged alternatively that it is focusing too much on the Iraq war or excessively on Indian issues, mostly the centuries-old Hindu caste system.

Iranian rights activist Shirin Ebadi, the 2003 Nobel Peace laureate, agreed with the Iraq focus but stressed there was more the meeting could discuss.

She said there was "not so much balance" in the selection of speakers, with the opening night seeing only one voice from Europe: British MP and anti-war activist Corbyn.

"This meeting is for a better world and needs to focus on all current international issues and one of the most important ones is the problem of Iraq," Ebadi told AFP.

She stressed the forum could also work to ensure universal protection of human rights and to ease income disparity around the world.