The Embassy of the United States in Switzerland is urging U.S. citizens to exercise caution after Geneva raised its terror alert level on Thursday following reports that four alleged Islamic militants are suspected of having made their way to Geneva.

In an online statement, the State Department recommends particular vigilance as well as attention to local reports on the state of security in the area.

In this time of elevated threat, the U.S. Embassy in Bern reminds U.S. citizens to review personal security plans; remain aware of surroundings at all times, and monitor local news stations for updates. We also recommend maintaining a high level of vigilance and take appropriate steps to enhance personal security.

The U.S. Overseas Security Advisory Council (OSAC), which liaises with the American private sector abroad on security issues, issued a similar warning as well as a tweet urging vigilance.

The Embassy also strongly recommends U.S. nationals residing in Switzerland to enroll in the U.S. Department of State’s Smart Traveler Enrollment Program (STEP). The program continuously circulates security updates and quickly connects citizens to embassies and consulates in emergencies.

STEP enrollment “makes it easier for the nearest U.S. embassy or consulate to contact you in an emergency,” the statement said.

The Geneva public prosecutor Olivier Jornot announced Thursday the opening of an investigation “on the basis of a terrorist threat in the Geneva region.” A close collaborator of Salah Abdeslam, one of the authors of the Paris attacks, was recently spotted in Geneva, according to reports.

Around 7:00pm Thursday, police evacuated the Renens train station and its surroundings after the discovery of an abandoned suitcase.

For security reasons authorities have also changed the venue for U.S.-Russian talks taking place Friday morning concerning the situation in Syria from the Palais des Nations to an undisclosed location.

The UN Director in Geneva, Michael Moeller, tried to reassure the UN staff while calling for vigilance. “There is no indication of a specific risk against UN personnel,” he wrote in an email to all staff late Thursday afternoon.

Follow Thomas D. Williams on Twitter @tdwilliamsrome