About 100,000 people attended the demonstration in the Yugoslav capital in support of demands that President Slobodan Milosevic resign.

Opposition leaders gave Mr Milosevic an ultimatum to step down within two weeks or face a sustained campaign of civil disobedience.

'Failed in every respect'

Serbian state run television downplayed the rally, saying it had "failed in every respect".

The BBC's Michael Williams: "Each demonstrator had their own grievance"

A commentary broadcast on Radio-Television Serbia said: "It is not known who is more disappointed: the organisers, the participants or the Nato bosses and tutors."

The government-run Politika daily, in an article headlined "Failed pro-Nato rally", said only 25,000 attended the event.

Addressing the first major anti-government protest in the capital for more than two years, Zoran Djindjic - leader of the Alliance for Change - threatened to have roadblocks erected across the country.

"We will hold our ground until our demands are met," he told the cheering crowd.

(Click here for an at-a-glance guide to the Serbian opposition)

Belgrade Correspondent Jackie Rowland: "Strategy seems to be to ignore the opposition"

In another dramatic development, Vuk Draskovic - leader of the Serbian Renewal Movement - also addressed the crowd , after initially saying he would not do so.

"We want Vuk, we want Vuk," chanted the crowd, booing off-stage the man deputised to speak on Mr Draskovic's behalf.

Demonstrators chanted "Slobo go" and "red bandits", and carried banners reading "You sold out Serbia" and "Slobo, please just go".

After initial doubts over its likely effectiveness, the rally proved unexpectedly dynamic.

The call for change is growing louder

Crucially, it has also served to present a more unified face for the opposition, with Mr Draskovic and Mr Djindjic speaking from the same stage.

A police presence was visible, but not as obvious as previously feared by opposition supporters and organisers.

James Robbins, Political Correspondent talking to BBC News

One small group of protesters staged a six-mile march on foot to the capital from their hometown of Pancevo.

"We are marching to Belgrade because we want to kindly ask Milosevic to leave," said Tibor Jona. "It's either him or us."

On Wednesday Belgrade police said they arrested a man with a "highly explosive device" and warned repeatedly of possible bombing attacks at "massive public gatherings" but opposition leaders accused the government of trying to scare people from the rally.

CHOOSE A NAME... Vuk Draskovic Zoran Djindjic Vesna Pesic Vuk Obradovic Vojislav Seselj Serbian Orthodox Church
	Anger in Serbia against President Milosevic has grown as a result of the Kosovo conflict. But the notoriously fractious opposition movement remains divided. For an at-a-glance guide to the key opposition figures and forces, pick a name from the pull-down menu above.

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