Massive colourful dominoes were placed along the former path of the Berlin Wall to mark the 20th anniversary of the opening of the barrier that divided the city for nearly three decades.

Many of the upright 7.5ft-high plastic foam dominoes, created by German students carried messages including "we are one people".

Approximately 1,000 dominoes, stretching for one mile, will be toppled on Monday as part of wider celebrations of the wall's fall.

One, labelled "bleeding heart", showed a sword cutting through the city of Berlin, starting a crimson flow of blood speckled with crosses.

"Everyone has walls in their heads to a certain extent," said Berlin resident Stefan Schueler. "It's always a good thing if one can break them down, and I think this is a good symbol."

Former Polish leader Lech Walesa, whose pro-democracy movement Solidarity played a key role in ending communism in Eastern Europe, is to tip the first domino on Monday to start the toppling of the display.

British Prime Minister Gordon Brown is expected to join US Secretary of State Hillary Clinton, French President Nicolas Sarkozy and Russian leader Dimitri Medvedev for the formal commemoration of the wall's opening on November 9 1989.

German Chancellor Angela Merkel, herself a resident of East Germany when the wall fell, said in her weekly podcast that it was a day that "changed the lives of many people, including me".

She added: "It is particularly nice for us to be able to celebrate this day with our European neighbours.

"We Germans will not forget our neighbours and allies who made the path to German reunification possible."