Police are out in force to prevent a repeat of last year's confrontation between the Swiss president and rightwing extremists on Swiss National Day, August 1.
The central town of Brunnen, the gateway to the Rütli Meadow – the cradle of Switzerland where National Day speeches are given every year, has been sealed off.
The police have set up checkpoints to prevent rightwing and leftwing extremists from entering the town.
The authorities said they banned more than ten people from entering the area by Monday evening. They also arrested one person with a flick knife and a can of tear gas.
The head of police for canton Schwyz said there was considerable potential for violence and local residents have been asked to report anything suspicious.
Hundreds of militants travelled to the Rütli Meadow last year where they jeered and heckled the speech by the 2005 president Samuel Schmid, booing when he referred to the importance of integrating foreigners.
Anyone wishing to attend this year's National Day celebration on the meadow has had to apply for a free ticket by submitting private data about themselves. By the end of last week, the organisers said they had refused 200 requests. Around 1,500 people are expected to attend.
A prominent member of a conservative lobby group leading the campaign to fight parliament's plans to tighten Swiss asylum laws will speak on the meadow this year.
Markus Rauh, former chairman of leading telecommunications provider Swisscom, has said the revised law is "shameful", calling on the Swiss to reject it in a nationwide vote in September.
Security is also expected to be tight in the town of Kerns, in canton Obwalden, where Justice Minister Christoph Blocher will give a speech. A member of the rightwing Swiss People's Party, Blocher is considered the architect of the harsher asylum legislation.
This year's president, the transport minister Moritz Leuenberger, made an appearance in the western community of Côte-aux-Fées on Monday before delivering the official government speech on radio and television on Tuesday.
The unusually hot, dry spell of the past few weeks has led the authorities in a dozen cantons to ban or limit fireworks, which are a key part of the August 1 festivities.
The strictest measures are in place in and around Zurich where not only fireworks but also charcoal barbecues have been banned.
Local police reported 70 infractions over the weekend and said about a dozen people received fines.
Other cantons, including mainly in western and southern regions of the country, are permitting fireworks displays only in designated areas under the watchful eyes of their respective fire departments.
In the capital, Bern, the organisers decided to cancel a planned bonfire apparently for safety reasons.
swissinfo with agencies
At the end of the 19th century, August 1 was proclaimed Swiss National Day but it only became a national holiday in 1994.
National Day marks the founding of the Swiss Confederation on August 1, 1291.
Three alpine states signed a treaty on the Rütli Meadow on that date pledging to act together to defend themselves against outside attack.
The Swiss celebrate National Day with brunches, speeches, bonfires and fireworks.