More and more Swiss cantons are imposing tough restrictions on the movements of asylum seekers who have committed crimes.
Police have been ordered to keep offenders away from town centres in a bid to crack down on crime.
Designated zones in the cantons of Bern, Geneva, Solothurn, Vaud and Zurich are off-limits to all "undesirables", not just asylum seekers.
However, the authorities are finding it hard to say whether the preventive measures are having any effect.
Zurich, like other cantons, wants to use the ban on entering certain areas to stop asylum seekers from committing crime.
The migration office (formerly the foreigners' police) has the power to keep out those who are not in possession of a yearly residence permit and who are suspected drug-dealers.
Since the beginning of December, unwelcome asylum seekers have been essentially barred from the city centre.
"As the city centre has only been a no-go zone since the beginning of the month, we cannot draw any conclusions," Marco Cortesi, press spokesman for Zurich police, told swissinfo.
Investigations have shown that only a minority of asylum seekers dabble in drug-dealing.
Since the middle of October 2002, curbs on movement have been applied in 60 cases in the canton.
Of the total, 30 were in the town of Winterthur, 11 in Zurich city and a further 11 in other parts of Zurich canton.
According to Cortesi, a restriction order is used to get people, who make a "negative" impression, off the streets.
This includes so-called down-and-outs, the homeless and others against whom a complaint has been made.
According to the migration office, the latest measure works as a deterrent - simply being threatened with a ban is sometimes sufficient to resolve a situation.
Human rights observers told swissinfo that Meilen in canton Zurich had gone as far as slapping a movement ban on an entire group of asylum seekers, preventing them from entering sports grounds and the city centre.
That was according to Walter Angst from the human rights organisation, Augen Auf, and Marc Spescha, lawyer and foreigner rights specialist.
An article in the Neue Zürcher Zeitung newspaper on December 12 also mentioned special permits for 80 asylum seekers from Meilen.
The local authorities denied any knowledge of such treatment. Spokeswoman Susanne Weber told swissinfo that there were no such orders in place.
However, discussions about the community's policy towards asylum seekers have been taking place between the cantonal police authorities and local Meilen officials.
The Federal Refugee Office said it, too, was concerned about how Meilen was dealing with asylum seekers.
Spokeswoman, Dominique Boillat, said the community "had become aware that its policies were causing concern".
She added that it was "important to take the fears of the [local] population seriously."
The legal basis for restricting movement can be found in a federal law on the rights of foreigners to stay in the country and to receive a residence permit, which came into force in 1995.
This gives the cantonal authorities the right to bar certain people, suspected of committing a crime, from public areas.
If the movement ban is not adhered to, the person in question faces up to one year in prison.
Until now, this legal provision has been used sparingly, a trend which seems now to have been reversed.
The Bernese authorities have gone one step further.
Since 1997, Bern has a cantonal provision within police law - the only canton to have such a provision - which allows the country's capital to restrict the mobility of undesirable Swiss citizens, as well as foreigners, who already have permission to remain in the country.
Since the beginning of this year, this power has been invoked in 300 cases in Bern, Biel and Thun.
The cantons of Basel, Geneva, Solothurn and Vaud have also issued such bans.
In Geneva, since the beginning of October asylum seekers who are suspected drug-dealers can be banned from the city centre for six months.
Since March, Geneva's police force have arrested some 440 asylum seekers - 90 per cent of whom originate from West Africa - and instigated nearly 100 urban and 175 cantonal restricted-movement orders.
Over 5,000 asylum seekers live in Geneva.
Canton Solothurn has effected 84 similar orders in the towns of Solothurn and Olten since the beginning of the year.
Abuse of human rights?
The European Court for Human Rights in Strasbourg recently decided two cases concerning restriction of movement in the Netherlands.
By a small majority, the judges decided that such orders in certain circumstances could be in the public interest and were consequently compatible with human rights.
swissinfo, Elvira Wiegers (translated by Faryal Mirza)