By Rob Broomby BBC Berlin Correspondent

A ceremony has taken place in central Berlin in memory of the victims of left-wing violence in Germany in the 1970s and 80s.

Today we reinforce what our common existence is based on - peaceful, free and democratic exchange of opinions, and a refusal to use violence

President Johannes Rau

The service, led by the federal President, Johannes Rau, marked the 25th anniversary of the freeing of more than 80 hostages from a hijacked German airliner in Mogadishu.

This event, on 18 October 1977, was a ray of hope in desperate times.

But the hostage release was followed by the suicides in prison of three leaders of the paramilitary Red Army Faction (RAF) - Andreas Baader, Gudrun Ensslin and Jan-Carl Raspe.

And the president of Germany's employers' association, Hanns Martin Schleyer, was then murdered by some of their supporters.

Fathers and brothers

The pilot of the Lufthansa jet had already been shot dead by Palestinian hijackers wanting to force the release of Red Army faction leaders from German jails.

One of the lawyers for the gang was today's interior minister, Otto Schily

The plane was stormed and everyone was freed.

The man who holds Martin Schreyer's job today, Dieter Hunt, says the main lesson of the events 25 years ago is that democracy and security are not guaranteed - they need to be struggled for by every citizen.

President Rau said all those murdered were fathers and brothers, life partners and colleagues, ripped from our midst in the middle of their lives.

German Autumn

The period was soon mythologised by the political left and became known as the "German Autumn".

Ulrike Meinhof, a key RAF leader, had already committed suicide.

One of the lawyers for the gang was today's interior minister, Otto Schily.

He said at the time he wasn't convinced it was suicide.

He has since changed his view.

Baader's lawyer, Christian Stroebele, today a Green Party Bundestag member, still doubts the official version, and many questions remain unanswered.

Film

But despite the release of a new film about Baader, which critics say glamorises the urban guerrilla leader, few will mourn their deaths.

With the prison suicides the leaders of the Red Army Faction had gone, but the killing continued.

Their last victim was murdered in 1991.

The now infamous "de-escalation agreement", just two and a half years ago, finally ended over two decades of political violence.