Demonstrations that began peacefully slipped out of control, as groups of protesters hurled stones and bottles at riot police, who responded with rounds of tear gas. Arrests A bank in a street close to the conference centre was briefly set alight. Some 20 police were reported injured in clashes, and seven protesters were arrested. The demonstrators are from a number of groups, including anarchists and anti-capitalists. Some condemned the Charter of Fundamental Rights, saying that it would not encourage higher standards of living and only offers a minimum level of rights.
Correspondents say there is a real risk of the summit failing.
It aims to streamline the EU's institutions and voting procedures, but some countries fear that they may lose influence in the name of more efficient decision-making. At present it is possible for each of the 15 member states to be represented on the commission, but it risks becoming unwieldy as new members join. The number of votes wielded by each country within the union is another point that is likely to prove contentious. Germany wants a larger share of the votes, proportionate with being the most populous country in the union. This has sparked a dispute between Germany and France - the two countries usually perceived as being at the core of the union.