Over 1,000 anti-racism protesters and immigrants have marched through central Athens to demonstrate against a plan to build a fence at the border with Turkey that aims to stop illegal immigrants from entering Greece.
The rally marched into a neighbourhood heavily populated by immigrants and where local residents have been complaining about their presence.
They were met by protesters from extreme right-wing groups who had gathered to block them. A heavy police presence blocked the main street of the area to keep the two sides apart.
Officers fired tear gas at the right-wing protesters, who threw stones and other objects. Clashes ensued between the rival demonstrators, and reached as far as the entrance of a local church, forcing some protesters to run into the church.
An estimated half a million illegal immigrants and asylum seekers live in the Mediterranean state of about 11 million inhabitants, many of them in Athens, and an increasing share of those trying to reach the EU come in through Greece.
Greece has a growing Muslim community and tensions between locals and incomers have run high in some areas.