May Day

Declared an international working-class celebration in 1889 Public holiday in many countries Celebrated in pagan times in Europe as the first day of spring

Police are on the alert for anti-globalisation protests across the world, with special attention focussing on London, where previous May Day events have degenerated into riots.

In France and Venezuela, demonstrations have taken on a special, political significance this year with rival marches planned by parties vying for power in both capital cities.

Police in Sydney described the disturbances outside Australasian Correctional Management (ACM) as "not major" despite scuffles as police on horseback forced back the protesters.

Protest organiser Zanny Begg said the aim had been to "imprison" ACM in its offices so that the company could "know what it feels like, in the way that they imprison refugees".

May Fayre

There were violent scenes at a much bigger rally in Berlin, Germany, on the eve of May Day.

Hundreds of police officers rushed into a crowd of about 5,000 at a rock concert after masked protesters reportedly broke into a supermarket and began looting it.

Police in Berlin were pelted with bottles and flares

Several officers were injured, but there were no reports of protesters being hurt at the rally in the Kreuzberg district, which has been a traditional event for years.

In London, about 6,000 police officers are on duty ahead of an anti-globalisation protest in the city's exclusive Mayfair district by about 10,000 people.

Some businesses have been boarding up their windows in anticipation of anti-capitalist violence, although organisers of the "May Fayre" have portrayed it rather as a carnival.

Features include a strolling circus and a mass football match.

Le Pen's May Day

With the run-off in France's presidential election falling this Sunday, May Day in Paris will see two huge rallies for and against far-right contender Jean-Marie Le Pen.

The leader of the National Front is leading the party's traditional march to honour France's patron saint, Joan of Arc.

Meanwhile, hundreds of thousands of people who oppose Mr Le Pen's views are due to march in protest at his success in reaching the run-off.

Police are hoping that the scheduled routes will keep the marchers safely apart.

	:	May Day in Paris
Detailed map of May Day marches

In the Venezuelan capital, Caracas, supporters and opponents of the controversial Venezuelan President, Hugo Chavez, are due to hold rival May Day rallies.

Previous protests against Mr Chavez's radical leftist policies have ended in violence with 17 people shot dead last month in unrest which removed the president from power temporarily.

May Day protests could spill over into unrest this year in other countries:

• In the Philippines, riot police are surrounding the presidential palace in Manila against supporters of Joseph Estrada, the imprisoned ex-president.
• In South Korea, tens of thousands of trades unionists will turn out in 10 major cities.