BERLIN - German President Horst Koehler paid tribute Friday to 70,000 East German citizens who braved a feared crackdown by communist security police and took to the streets of Leipzig in a historic demonstration 20 years ago.

The pro-democracy rallies in the city led directly to the breaching of the Berlin Wall less than a month later and German unification in October 1990.

On October 9, 1989, 20 years ago, the people of Leipzig showed us what citizens can achieve when they believe in their own strength and take their destiny into their own hands, Koehler said at a ceremony in a concert hall in Leipzig, attended by Chancellor Angela Merkel and other high-ranking politicians.

In those October days, everything was on a knife's edge ... people had to expect the worst because there were clear threats, Koehler said, recalling fears the crowds would be crushed with the same brutality as pro-democracy protestors around Tiananmen Square, Beijing four months earlier.

But the revolution stayed peaceful, he said.

In the early autumn of 1989, Monday prayer meetings for democracy and justice filled a central Leipzig church with political dissidents, would-be emigrants and ordinary East Germans caught up in the growing wave of defiance.

Monday demonstrations followed in the town center, reaching a peak on October 9 when 70,000 people openly challenged the communist authorities by taking to the streets.

These demonstrations grew in size and spread throughout East Germany, eventually leading to the fall of the Berlin Wall.

The citizens of East Germany knew they did not want to continue living without freedom, living narrow and dismal lives, said Koehler. This is why it is important to keep the memory of the East German dictatorship and the resistance against it alive.

(Reporting by Sarah Marsh; editing by David Stamp)