Geneva officials raised the city's threat level on Thursday and were looking for suspects identified by Swiss federal authorities in connection with ongoing terrorism investigations.
"The Geneva police, on the basis of this information, have increased their level of vigilance and reinforced the number of police agents on the ground," the Geneva department of security said in a statement.
It said on Wednesday afternoon the Geneva authorities had been alerted by the Swiss federal authorities to "suspect individuals likely to be located in Geneva or the region". Investigations are continuing in close collaboration with national and international forces, it continued. Border forces have also been stepped up.
"We have gone from a vague threat to a precise threat," Emmanuelle Lo Verso, spokeswoman at the security department, told Swiss public radio, RTS.
It was not immediately clear from the Geneva security department statement, however, whether the suspects were directly linked to terror attacks in Paris on November 13. The Geneva spokeswoman said she had no further comment. Later, according to Reuters, a spokesperson for the federal police said they had no information linking the Geneva suspects to the events in Paris.
A spokesperson for the federal police in Bern said later that the formulation of the original announcement by Geneva authorities had been "clumsy" and that his department had only warned them of a terror threat, not of any link to the Paris attacks.
A security guard at the United Nations in Geneva told Reuters that Swiss authorities were searching for "four guys" believed to be in the area. UN security guards were stationed with MP5 sub-machine guns at entry points for cars, a highly unusual measure at the sprawling complex.
In a statement released on Thursday afternoon the Geneva public prosecutor's office said it had opened a criminal investigation into the preparation of illegal acts. This provision targets "anyone who takes steps, technical or organisational, to commit a serious crime", it declared.
French-language newspapers Tribune de Genève and Le Temps both reported that a van with Belgian plates was seen and tracked by police in the Geneva region on December 8. The passengers are believed to have been under surveillance by French authorities for ties to radical Islamic groups. The van and the passengers are believed to have left Switzerland in the days since and it is unknown whether they have any ties to the four suspects currently being sought by Geneva police.
The border police has stepped up its surveillance to maximum capacity in the Geneva region, according to Michel Bachar, a spokesperson for the Swiss border police.
According to Swiss Public Television, RTS, Geneva police asked the Israeli community in Geneva to be on heightened alert on Wednesday morning in the face of a specific threat. As a result, security was also heightened around schools and community buildings of the Israeli community.
The American embassy in Switzerland also released a security statementexternal link in which it reminded US citizens to "review personal security plans; remain aware of surroundings at all times, and monitor local news stations for updates". The embassy also recommended maintaining a high level of vigilance and taking "appropriate steps to enhance personal security".
Three-way talks between Russia, the United States and the UN on the Syria crisis in Geneva due to take place on Friday have been moved to a secret location, RTS reported.
Wake of Paris attacks
Shooting and bomb attacks claimed by Islamic State killed 130 people in Paris on November 13. Police in several European countries are still searching for individuals believed to have been involved in the attacks or in their planning.
Last week Pierre Maudet, Geneva’s head of the department of security and economic affairs, told reporters that the level of alert had been raised in the canton following the Paris attacks but said that Geneva was not threatened.
“I can affirm that Geneva is not threatened on the basis of the information we have,” he told reporters. “Switzerland is not top of the list of potential targets of terrorists.”
But he said the canton, which has a 100km border with France, an international airport and home to numerous international organisations, including the European headquarters of the United Nations, had stepped up its vigilance and cooperation with neighbouring France. Security measures have also been tightened at the airport.
On Thursday evening, Maudet said the security arrangements would be renewed "while the more precise threat still exists".
Geneva’s police chief Monica Bonfanti told reporters that 1,400 police were trained to deal with emergency situations like terrorist attacks.
swissinfo.ch with agencies