Hamburg  - President Horst Koehler marked German Unity Day on Thursday with a call to the country to live up to its expectations in Europe.

Germany's national day, a public holiday, marks the reunification of the two Germanys 18 years ago.

"There is no reason for us to make ourselves bigger than we are, but not smaller either," Koehler said in an address delivered in the northern port of Hamburg, where the main celebrations were held.

This responsibility demands "that we make clear in the European Union what we want as a German nation ... but at the same time show a readiness to coordinate interests with our partners," he said.

Koehler, who also hosted a reception for dignitaries from Germany's 16 federal states, said "the European model" was of vital importance in times of global upheaval.

Hamburg also marked the event with religious services and a three- day civic festival opened by the city's governing mayor, Ole von Beust.

Some 1,500 left-wing demonstrators gathered in Hamburg to protest the Unity Day celebrations, but police reported no violent incidents by mid-afternoon. (dpa)