The citizens of Berlin on Sunday released almost 7,000 balloons into the night sky, many carrying messages of hope to mark the 25th anniversary since the fall of the wall that once divided their city.

The symbolic act recalled the giddy night of Nov. 9, 1989, when thousands of people from the communist East streamed through the Berlin Wall to celebrate freedom with their brethren in the West.

"For peace and freedom," Berlin mayor Klaus Wowereit told a crowd of ten thousands that had gathered at the city's iconic Brandenburg Gate as he gave the signal to release the balloons, which has been placed, illuminated, along a 15-kilometer (9-mile) stretch of the former border.

Earlier he thanked the former leaders of Poland, Hungary and the Soviet Union — Lech Walesa, Miklos Nemeth and Mikhail Gorbachev — for having helped set the stage for Germany's peaceful revolution.

Gorbachev — who is still a popular figure in Germany — was greeted with affectionate shouts of "Gorbi, Gorbi" by the crowds.

Hours earlier German Chancellor Angela Merkel had honored the memory of the 138 people who died along the Berlin Wall, and the countless others who suffered during its 28-year existence.

The latter included Dorothea Ebert, a violinist who was imprisoned in East Germany after a failed attempt to escape. On Sunday, Ebert played a piece by Bach that she had practiced over and over during her imprisonment — on an imaginary violin, because the communist authorities refused to let her have a real one.

Merkel also paid tribute to those who helped bring down the wall, calling its collapse an example of the human yearning for freedom.

"It was about reclaiming freedom, about being citizens, not subjects," Merkel said at the main memorial site for the wall on Bernauer Strasse.

The protests that forced East German authorities to relax travel restrictions for their citizens were spurred by changes that had already taken place elsewhere in Eastern Europe. Merkel said the wall's collapse should be regarded as a sign of hope for people suffering in Ukraine, Syria and Iraq.

"The fall of the wall has shown us that dreams can come true," said Merkel, who grew up in East Germany. "Nothing has to stay the way it is, however big the hurdles are."

Merkel noted that Nov. 9 is a significant date in German history also for being the day when, in 1938, Nazi paramilitaries launched a pogrom against the country's Jewish population in what became known as Kristallnacht — the "Night of Broken Glass."

"That was the opening note for the murder of millions," said Merkel, adding that on Nov. 9 each year "I feel not just joy, but the responsibility that German history burdens us with."