Germany sought "forgiveness" from families of victims in the Munich Olympics attack 50 years on, admitting responsibility for a litany of failings that led to the deaths of 11 Israelis.

"As head of state of this country and in the name of the Federal Republic of Germany, I ask you for forgiveness for the lack of protection of the Israeli athletes at the time of the Olympic Games in Munich and for the lack of clarification afterwards, and for the fact that what happened, happened," said President Frank-Walter Steinmeier.

Today marks the 50th anniversary of an attack by Palestinian gunmen on the Israeli team at the 1972 Munich Olympics.

The attack, associated with the Palestinian militant group Black September, shocked the world with large parts of it playing out on live television, watched by millions of viewers.

Last night, the German President admitted that it was "shameful" that it took five decades for Berlin to agree compensation for the bereaved families of the Israeli victims.

"That it took 50 years to reach this agreement in the last days is indeed shameful," he said, standing next to his Israeli counterpart Isaac Herzog.

At a separate ceremony this morning at the Olympic village where the Israeli team was staying, Munich mayor Dieter Reiter apologised for the "momentous mistakes" made by those responsible for the Games.

"I am sorry for that and I apologise for the fact that after the attack, what would have been demanded by humanity was simply not done - admitting the mistakes and taking responsibility for them."

Ankie Spitzer, the widow of murdered Israeli fencing coach Andre Spitzer and Ilana Romano, widow of Israeli weightlifter Yossef Romano, gather to commemorate the 50th anniversary of the attack

A row over the financial offer previously made by Berlin to victims' relatives had threatened to sour the ceremony, with families initially planning a boycott.

However, a deal was finally agreed on Wednesday, offering €28m in compensation.

It also for the first time saw the German state acknowledging its "responsibility" in failings that led to the carnage.

What happened on 5 September 1972?

The attack began in the early hours of the morning, when eight gunmen from the Palestinian militant group Black September stormed into the Israeli team's flat at the poorly defended Olympic Village in Munich, shooting two people dead and taking nine Israelis hostage.

West German police responded with a bungled rescue operation, in which all nine hostages were killed, along with five of the eight hostage-takers and a police officer.

An armed police officer in the Athletes' Village during the incident

The Games were meant to showcase a new Germany, 27 years after the Holocaust, but instead opened a deep rift with Israel.

Ten years ago, in 2012, Israel released 45 official documents on the killings, including specially declassified material, which lambasted the performance of the German security services.

Included in the reports was an official account from the former Israeli intelligence head Zvi Zamir who said the German police "didn't make even a minimal effort to save human lives".

What went wrong?

The armed attackers demanded the release of more than 200 Palestinians held in Israeli prisons, as well as that of the German Red Army Faction radicals Andreas Baader and Ulrike Meinhof as well as a plane to the Middle East.

An initial rescue attempt was called off when German police realised it was being broadcast live on television.

Authorities subsequently agreed to take the attackers and a number of hostages to the airport.

There, a further rescue attempt also failed with a firefight breaking out at Furstenfeldbruck Air Base.

The airbase fight finally ended when the surviving gunmen were captured. By the end of the bloody 24-hour standoff, 11 members of the Israeli team were dead along with a German police officer and five of the Palestinian gunmen.

The long battle for compensation

Over the years, the relatives of the victims of the attack battled to obtain an official apology from Germany.

They also wanted access to official documentation and compensation beyond the initial €4.5m offered.

As recently as two weeks ago, relatives of the victims said they were offered €10m - including the €4.5m already given.

"I came home with the coffins after the massacre," Ankie Spitzer, whose husband Andre Spitzer was killed in the hostage-taking, told AFP. "You don't know what we've gone through for the past 50 years."

Israeli President Isaac Herzog said the bereaved relatives had simply "hit a wall" over the years whenever they tried to raise the issue with Germany or even with the International Olympic Committee.

"I think there was tragic suppression here," he said, noting the litany of failings that were "inhuman and incomprehensible" such as "the fact that the hostages were being led to slaughter and the Games went on".

He was referring to a decision by the then-IOC president Avery Brundage who declared that "the Games must go on," following only an initial suspension.

President Herzog voiced hope that the agreement on compensation would bring "this painful episode to a place of healing".

"I hope that from now on, we shall continue to remember, invoke, and most importantly reaffirm the lessons of this tragedy, including the importance of fighting terror, for future generations," he said.

Tomorrow, he will also address the Bundestag and visit the Nazi concentration camp Bergen-Belsen, where his late father and former Israeli president Chaim Herzog was counted among the liberators as a British army officer in 1945.

Additional reporting AFP