Anarchist youths have disrupted a largely peaceful protest in Athens by trade unions over government economic reforms.

The anarchists attacked police with stones and rocks and police responded with tear gas before chasing them through the streets of the Greek capital.

Some of the protesters joined in the violent skirmishes, which carried on down one of Athens' main streets.

The youths smashed a parked car and set rubbish bins on fire.

About 12,000 people took part in a string of marches in Athens, down from 50,000 in the biggest demonstration in May against a 110 billion euro bailout for the debt-laden nation from the European Union and the IMF.

Two separate rallies took place by the public and private sector trade unions, ADEDY and GSEE, as well as unions affiliated with the Communist Labour Front.