A UN security official in Geneva has said that they had raised the alert level in the city and were looking for suspects in connection with investigations into the Nov. 13 Paris attacks.
One of the security officials said on condition of anonymity that the Swiss authorities were searching for four people believed to be in the city, which was close to the French border or nearby.
Another officer said that the UN compound was on maximum alert.
The Geneva department of security also said in a statement that Geneva police and their partners were actively looking for people whose description had been provided by the Swiss confederation.
It said this was as a result of investigations carried out following the Paris attacks at the international and national level.
Shooting and bomb attacks claimed by Islamic State killed 130 people in Paris on Nov. 13.
It said that police in several European countries were still searching for individuals believed to have been involved in the attacks or in their planning.
A source said that the UN security guards in Geneva, the European headquarters of the world body, were stationed with MP5 sub-machine guns at entry points for cars.
The source described the situation as a highly unusual measure at the sprawling complex near the French border.
Meanwhile, Swiss and French officials said that they have been working closely together since the Paris attacks.