Protesters have taken to the streets of Athens, Greece. They are campaigning against government cuts to tackle the country's crippling debt.
Thousands of Greeks are taking part in May Day rallies called by trade unions and left-wing parties.
Readers of the BBC News website have been describing the situation.
I was on the march in Thessaloniki, northern Greece. There were some attacks on banks and multi-national owned franchises but generally speaking the atmosphere was peaceful.
Craig Wherlock, Thessaloniki, Greece
Having been in Greece for four months of study, the most sensational aspect of these protests is how normal everyone seems to think they are. 50 feet from rock-throwing anarchists, I saw a family enjoying May Day by strolling with a child in a baby carriage. Greece is far from widespread chaos. The protesters turn a two block radius into a war zone while allowing their great uncle to still enjoy his black coffee at a cafe a block away!
Jimmy Hagan, Youngstown, Ohio, USA
I live in a medium-sized town and so far, the protests have been peaceful. A minority of the electorate, including the communists, is the most vocal and therefore headline-making group. These protests are acceptable to the point of defusing popular anger at the austerity measures, but not to the point of violence, of course.
I believe that the government has no choice but to implement the measures, as demanded by the IMF and the EU. They are, however, harsh, as most Greeks are already low-paid. Wage cuts of about 20% and VAT rises. Try to sell that to people who have to sustain a family with 1200 euros a month.
George, Ioannina, Greece
My friend and I have seen the burnt out van and other damage nearby. But the demonstrations taking place in Syntagma Square in front of the Parliament Building have been very orderly and well-behaved, with the police keeping a low profile. It is hard to support the demonstrators when one knows what a dire state the Greek economy is in. They are burying their heads in the sand if they believe that the economy can be put right without a degree of economic pain being inflicted on everyone.
Anne Morden, Wokingham, England
I've witnessed the 'riots' and think the press has blown them out of proportion. They're not as bad or widespread as described. As for the cuts that have to be made, I think they are necessary. I also think that the European parliament has imposed too much. I hope they won't destroy this country.
Al Watson, Athens, Greece
The protesters passed me on Piraeus Street on their way to the Finance Ministry. Numbering a couple of hundred at most, it was a noisy but small demonstration with far less support than recent anti-racism marches. As usual in these situations there was a large element of "koukouloforoi": youths using hoods or bandanas over their faces to avoid identification during the clashes. Elsewhere there were other protest marches - mostly union-led - which passed off peacefully.
Meanwhile, the majority of Athenians on the streets were sitting outside cafes and restaurants, enjoying the Mayday sunshine with friends. But with coffee already costing upwards of 4 Euros in central Athens, it remains to be seen how long the average Greek will be able to sustain their standard of living.
Dave Bindon, Athens, Greece