Switzerland acknowledged Thursday that the past forced removal of children from the nomadic Yenish and Sinti communities amounted to a "crime against humanity".
It is the first time that Switzerland has made such an acknowledgement, with interior minister Elisabeth Baume-Schneider calling it "a very dark page in our history".
The Swiss government estimated that around 2,000 people were removed from their families and placed elsewhere.
"The government recognises that the acts perpetrated within the framework of the 'Aid Organisation for Children of the Road' must be qualified as a 'crime against humanity' under current international law," it said in a statement.
The government "reaffirms the apology it made in 2013, to those affected, for the injustices committed", it added.
The interior ministry "will clarify with them to what extent there is still a need to deal with the past beyond the measures already taken".
Switzerland said that up to 1981, more than 100,000 children and adults had been affected by compulsory welfare measures or extra-familial placement in foster care.
"The victims of these acts were people from disadvantaged backgrounds or whose lifestyles did not correspond to the social norms of the time," the statement said.
Among them were people with an "itinerant lifestyle", such as the Yenish and the Sinti.
Switzerland recognises the Swiss Yenish and Sinti as national minorities.
The Swiss culture ministry says: "Nomadic life shapes the identity of the Yenish and Sinti in Switzerland, even though many families have permanent homes nowadays. Many family groups still travel during the summer months, living and working in caravans."
- Forced sterilisations -
The main actor in the child removals was the "Aid Organisation for Children of the Road" programme run by the Pro Juventute charitable foundation.
Between 1926 and 1973, those running the operation removed around 600 Yenish children from their parents and forcibly placed them in homes, educational institutions and foster families, with the help of the authorities.
Sinti children were also affected.
In addition, adults who had been placed in foster care when they were children were "placed under guardianship, housed in institutions, banned from marrying and, in individual cases, forcibly sterilised".
Besides Pro Juventute, religious charities and authorities were also involved, leading the government to estimate the number of placements at "around 2,000".
Following appeals from representative groups, the government commissioned an expert independent legal opinion -- from Oliver Diggelmann, professor of public international law at the University of Zurich -- as to whether Switzerland bore responsibility for genocide or a crime against humanity.
"The conclusion of the legal opinion is that the removal of children as well as the desire to break family ties in order to eliminate the nomadic way of life and to assimilate the Yenish and Sinti must be qualified as 'crimes against humanity'," the government said.
Baume-Schneider said: "Crimes against humanity are understood to mean a widespread or systematic attack directed against any civilian population."
It is the first time that Switzerland has acknowledged its responsibility for a crime against humanity, noted Diggelmann.
"This step is wonderful and opens doors that have long been closed," said Isabella Huser, a Yenish writer and member of the Federal Commission against Racism, quoted by the domestic Keystone-ATS agency.